2680A2686A General Specifications

Table 1-1 provides the general specifications for the 2680A and 2686A devices. Table 1-1. 268XA General Specifications Table 1-1. 268XA General Specifications Maximum of 120 channels (Precision or Fast Analog Input) per chassis 20 digital input and outputs channels, 8 double pole-single throw relay channels, a totalizer input, and a totalizer enable input. 473 mm (18.6 in) x 423 mm (17 in) x 237 mm (9.3 in) 2680A 2686A (empty) 8.5 kg (18.9 lb) 2680A - FAI 0.8 kg (1.8 lb) 2680A - PAI 1.2 kg (2.7...

2686A PC Card Storage

The 2686A supports a non-volatile PC Card (PCMCIA ATA type card) memory module option. This table provides a list of active channels and the number of scans to memory card capacity. The standard Controller card will store approximately 600,000 readings. Table 1-6. 2686A - Active Channels and Number of Scans to Card Capacity Table 1-6. 2686A - Active Channels and Number of Scans to Card Capacity Estimating space 80 bytes scan + 4 bytes channel scanned (allow 4.5 overhead for card formatting)

268xa

Data Acquisition System Data Logging System 2002 Fluke Corporation. All rights reserved. Printed in USA All product names are trademarks of their respective companies. Limited Warranty and Limitation of Liability Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service. The warranty period is one year and begins on the date of shipment. Parts, product repairs and services are warranted for 90 days. This warranty extends only to the...

4

Figure 4-4. 4-Wire Connections to the Universal Input Module (5700A) 4. Verify Accuracy Configure the Decade Resistance Source for the output values below and verify the Spy window measurement is between the minimum and maximum values. Change the channel 1 range as required (see Step 2). The resistance accuracy in this table makes allowance for up to 0.01 decade resistance tolerance.

4Wire Resistance Accuracy Test FAI Module

Connect the Resistance Source to Channels 1 and 11 Remove the Universal Input module from the device and connect a cable from the Decade Resistance Source to the Universal Input module terminals for channel 1 (Sense) and channel 11 (Source) as shown in Figure 4-3. Reinstall the Universal Input module. You may also use the 5700A resistance calibration output instead of the Decade Resistance Source. Tables are provided for both connections. Refer to Figure 4-4 for the 5700A 4-wire connections. 2....

5

Figure 2-2. 268XA Main Supply Circuit The 4004 PCA is the main board in the 268XA chassis. It contains the main switching power supply and various secondary power supplies, as well as all of the out-guard digital control circuitry, guard-crossing interface and host computer interface, both 10 100 Base T Ethernet and RS-232. Refer to Chapter 8 for a schematic of the 2680A-4004 board. Table 2-1 provides a summary of all the connectors on the 4004 PCA. Table 2-1. Controller Connector Description...

A3 Kernel

If the microprocessor detects a fault, it drives the HALT* signal low and in essence halts itself. Monitor the HALT* line and if it is not steady and toggles between low and high, then there is most certainly a problem with the A3 kernel. In this instance, check the pull-up resistors for the data and addressing lines, and then signal conditions at the kernel devices. Incorrect jumper settings (Table 6-12) can also cause kernel problems. Table 6-12. A3 A D Converter PCA Jumper Positions Table...

AC Fuse Replacement

The device uses a 1 2 ampere, 250 V, slow blow line fuse in series with the mains power supply. To replace the fuse, refer to Figure 3-1 and the following procedure To avoid electrical shock, do not operate the device without the cover properly installed. 1. Disconnect all rear panel cables to the device power, Universal Input modules, and I O connectors. 2. Locate the fuse holder at the back of the chassis near the power input connector and twist out the fuse. 3. Insert the new fuse into the...

Accuracy Performance Tests

The accuracy performance tests assume you have completed the Performance Test Setup described earlier in this chapter. Do not begin the tests until the device has been temperature stabilized for a minimum of one hour. The tests for the Master Alarm output, Trigger Output, Trigger Input, and DIO signal lines can either be tested using Fluke DAQ software or using commands through the RS-232 port. For the RS-232 tests, you will also need to use a program such as HyperTerminal to perform the test....

Analog Digital Converter Circuit

The A D converter consists of a gate array for control, switches for directing currents, and a reference circuit and reference resistors for providing the currents. The various currents are integrated across capacitor A3C44, and the zero crossing is detected by comparator A3U11 and a logic signal returned to the FPGA (Field Programmable Gate Array). The FPGA contains counters that count the amount of time that the reference currents are applied to the integrator. The input voltage is...

Analogto Digital ad Converter

The dc voltage output from the signal conditioning circuits is applied to a multi-slope A D converter. The input voltage is applied to a buffer integrator that charges a capacitor for an exact amount of time. During this time, positive and negative reference voltages are alternately applied to the integrator. The references are switched in a sequence controlled by the A D Electrically Programmed Logic Device (EPLD) (A3U18), which prevents the integrator from saturating. The amount of time that...

Auto ranging

The configuration of each channel includes the state of autoranging for that channel, either enabled or disabled. When performing a measurement on a channel that has autoranging enabled, the instrument first attempts a measurement on the range that was used on that channel for the previous scan. If this results in an overrange or underrange, the instrument up-ranges or down-ranges accordingly. Channels that are configured with autorange enabled, but have not yet been measured start on the...

Autozero

Autozero is the state the a d idles in when not in use. In this state, the signals PREF, NREF, DREF, and INT are all low. The purpose of the state is to remove any remaining charge on A3C44, to charge A3C60 to a voltage so that pin 6 of A3U19 is at zero, and to provide time to return data to the microprocessor. In this state, the input is not connected, A3R94 and A3R95 ground the input, A3U19 produces an error signal, which is amplified by the other halve of A3U19, providing feedback to produce...

Background Testing

Background testing is performed to ensure that communication, configuration, and calibration constants do not become corrupt over time. Every 10 seconds, one of the parameter sets is verified (verifying all parameter sets at once is too CPU intensive). The following parameter sets are checked FLASH ROM communication parameters FLASH ROM calibration constants RAM device and channel configuration RAM pre-computed range scaling and calibration constants used in evaluation RAM copy of calibration...

Calibration

The 2680A 2686A device features module calibration that is performed over the RS-232 interface using ASCII characters. It is not necessary to open the module case. Each analog A D module must be calibrated separately. Using known reference sources, closed-case calibration has many advantages. There are no parts to disassemble, no mechanical adjustments to make, and the module can be calibrated by an automated calibration system. The modules should normally be calibrated on a regular cycle,...

Channel MUX

The channel multiplexing consists of treeing and channel switches, implemented with either FET switches (FAI) or reed relays (PAI). There are two sets of bits associated with these switches. The tree bits must be set to indicate which bank of channels is being used where bank 0 is channels 1 to 10, and bank 1 is channels 11-20. For four-wire ohms measurements, both banks are selected. The position of the tree switches is also a function of the channel function and range being measured. The...

COMM Parameter Reset

To reset all the communication parameters to the factory defaults (Table 6-5), turn off the instrument, then turn the power on again while holding down the front panel COMM key. After the device beeps, and the message rESEt is displayed for one second, release the key. Table 6-5. Device Default COMM Parameters Table 6-5. Device Default COMM Parameters

Command Processing

The device RS-232 interface processes input and output in a manner similar to NetDAQ. The device receives a command or query from the host. The device returns a response to a valid query. The device always returns a prompt after processing an input line (the prompt follows the response in the case of a query). An input line to the device consists of one or more semicolon-separated commands followed by an input terminator. The device will accept CR LF or LF as the input terminator. The device...

Control Signals

Several signals are used by the A3U5 A D microprocessor to control and receive state information from the A D state machine (A3U18). The Trigger line, used to indicate to the A D when to begin a reading, was discussed previously. The A D state machine has several modes of operation perform conversion (measure input) do a reference balance reading with both references on or do a reference balance reading with both references off. These modes are selected by the A3U5 A D microprocessor through a...

Counters

The counters in the A D state machine (A3U18) are accessed through a synchronous serial interface. This interface is connected to the SCP port of the A3U5 A D microprocessor, which is also connected to the Stallion chip. Chip-select lines are used to indicate the device the A3U5 A D microprocessor is communicating. The counter values from the A D are transmitted in five bytes. The hardware state machine transmits bytes most-significant bit first. There is no hardware detection of overload. An...

DC Volts and Thermocouples Measurement Circuitry

For 3 V and lower ranges, the input to Stallion (A3U30) are as follows for signal HI and signal LO inputs HI is a direct input via the HI SENSE line A3R111, A3K26, A3R130, and pin 50 (HI1) input of A3U30. LO is an input to LO SENSE via A3R132 to pin 80 (LO2) of A3U30. For the 30 and 300 volt range, the input to Stallion (A3U30) are as follows for the HI and LO signal inputs The HI signal is scaled by A3Z7. The input is applied to pin 1 of A3Z7 and a 101 1 divider is formed by the 10 MW 100 kW...

Deintegrate1

Deintegrate1 is when the remaining charge of the capacitor is removed and the major count is completed. The input is turned off and no longer affects the reading. INT is off, PREF, and NREF continue to switch a few more times, and the signal is brought very close to zero. The previous integrate state ended in a hold (both references off) and this state begins with the PREF signal on. The comparator is examined after each count and as soon as CMP goes low, a hold state begins with both...

Deintegrate2

Deintegrate begins with the turning on of DREF. This reference applies 1 16th of the current of NREF so the approach to zero is slower and more accurate. Correspondingly, the internal FPGA counter counts this time at 1 16th the value of NREF time. The count ends as the final state of the comparator (CMP) goes low, indicating that the charge has been removed from the capacitor. This also ends the count accumulation in the FPGA counters. The deintegrate2 state always takes 24 counts even though...

Device Configuration

The FUNC command is used to select a measurement function, range, and number of terminals on channel one only. When executing the *RST or *TST command, or when exiting calibration mode, the device sets the configuration to the values shown below in Table 6-6 Channel 1 to 20 configuration function, range, terminals, TC type, RTD R0 The prompts provide error information. The *TST query provides failure information. Power-on selftest results can be retrieved with the SELFTEST query.

Diagnostic Testing and Troubleshooting

Servicing Surface-Mount Error FLASH ROM Parameter Background Retrieving Error Codes using Selecting the Diagnostic Diagnostic Tool Diagnostic Tool Diagnostic Tool Diagnostic Tool Diagnostic Display COMM Parameter Using the RS-232 Command Device Command Troubleshooting the General Sys Ctrl PCA Troubleshooting the Sys Ctrl PCA Digital Troubleshooting the RS-232 Troubleshooting the Ethernet Troubleshooting the Keypad, Master Alarm Output, Trigger Input, and Trigger Out Troubleshooting the Power A2...

Diagnostic Tool conF

The conF diagnostic tool allows you to configure the reading rate, and channel functions and channel ranges for channels 1 to 20. Complete the following procedure to configure the reading rate and channel functions. 1. Select the conF diagnostic tool using the procedure Selecting the Diagnostic Tool Menu. 2. Reading Rate Use the up down arrow keys to show rAtE in the primary display then press the enter key. Using the up down arrow keys, sequence through the reading rates SLO (Slow), FASt...

Diagnostic Tool dio

The dio diagnostic tool allows you to change the status of any 20 dio lines dio19 to dio0 located in the DI O module. Complete the following procedure to change the status of any dio line. 1. Select the dio diagnostic tool using the procedure Selecting the Diagnostic Tool Menu. 2. Use the left right arrows to select the desired dio line dio19 to dio0. The format is nnnn-nnnn-nnnn-nnnn-nnnn, representing dio lines dio19 to dio0, respectively. The secondary display shows the selected line, for...

Diagnostic Tool idS

The idS diagnostic tool allows you to view the firmware versions installed in your device. Complete the following procedure to view the firmware versions in your device. 1. Select the idS diagnostic tool using the procedure Selecting the Diagnostic Tool Menu. 2. With inStr shown in the secondary display, and the device model number shown in the primary display, press the up down arrow keys to sequence through the firmware selections shown in Table 6-4. Table 6-4. Device Firmware Descriptions...

Diagnostic Tool rELAy

The rELAy diagnostic tool allows you to change the status of any 8 relay lines RLY7 to Complete the following procedure to change the status of any relay line. 1. Select the rELAy diagnostic tool using the procedure Selecting the Diagnostic Tool Menu. 6. Use the left right arrows to select the desired relay line RLY7 to RLY0. The format is nnnn-nnnn, representing relay lines RLY7 to RLY0, respectively. The secondary display shows the selected line, for example, RLY 7. 7. Use the up down arrow...

Digital Input Buffers

The Digital Input Threshold circuit sets the input threshold level for the Digital Input Buffers and the Totalizer Input. A fixed value voltage divider (R5, R6) and a unity gain buffer amplifier (U1) are the main components in the circuit. The voltage from the divider (approximately +1.4 V dc) is then buffered by U1, which sets the input threshold. Capacitor C8 filters the divider voltage at the input of U1. The 20 Digital Input Buffers are identical in design but only components used for...

Digital Input Output Tests

All configuration for the Digital Input Output Tests is done using the Communications dialog. To change DIO settings, click the DIO module icon in the TreeView display. Use the Spy function to monitor DIO settings. The Digital Input Output Tests check the 20 Digital I O lines on the Digital I O connector for output and input functions. See Figure 4-5 for the layout of the DIO connector module.

Digital Output Drivers

Since the 20 Digital Output Drivers are identical in design, the following example description references only the components that are used for the Digital Output (D0< 0> ). The Microprocessor controls the state of the Digital Output Driver DO< 0> by setting the level of the output U4 Pin 59. When U4 Pin 59 is set high, the output of the open-collector Darlington driver (U13 Pin 13) sinks current through current-limiting resistor R80. When U4 Pin 59 is set low, the driver output turns...

DIO Module Troubleshooting

To access this card for test, the user may need the 2680A-7001K Extender kit, PN 1619174. No calibration is required for this module. Problems can occur either with communication to the SYS CTRL card or with individual DIO, relay, or totalizer inputs. A Texas Instrument MSP430P337A micro controller, U4, is the heart of the DIO PCA. A quartz crystal operating at 32.8 kHz provides the main clock signal for the micro controller. This signal is internally multiplied to 3.6925 MHz for clocking of...

Error Detection

At power-up, the device software performs self-tests. If any errors in device operation are detected, they are reported on the device front panel with Error in the primary display and a decimal error code number in the secondary display. If there is more than one error, they are displayed sequentially. Selftest errors can be retrieved from RS-232 commands and the network. A selftest includes a test of the following items FLASH ROM parameters, communication parameters and calibration constants....

Fast Analog Input Fai Ad Specifications

This section includes specifications specific to the FAI A D instrument by measurement function. FAI A D DC Voltage Measurement Specifications The following tables provide FAI A D specifications for the dc voltage measurement function. Table 1-22. FAI A D DC Voltage General Specifications Table 1-22. FAI A D DC Voltage General Specifications 100 MW in parallel with 300 pF maximum for ranges < 3 V 10 MW in parallel with 100 pF maximum for ranges > 3 V 50 dB minimum at 50 Hz 60 Hz +0.1 , Slow...

Flash Rom Parameter Defaults

The FLASH ROM (System Power Controller Board 2680A-4004) parameters are reset to defaults following the first power-on and following power-cycles after any FLASH ROM parameters are discovered to be corrupt. These defaults are listed in Table 6-2. Table 6-2. FLASH ROM Parameter Defaults Table 6-2. FLASH ROM Parameter Defaults All gains are set to 1.0 all offsets are set to 0.0

Fluke DAQ Digital Input Output Test

Open Communication Dialog Use the Communication dialog in Fluke DAQ for this test. Click on the DIO module icon in the TreeView display to see the DIO settings. The DIO dialog will only work if the DIO module is installed in the device and has been inserted using the Configuration dialog. 2. Set Signal Lines Low Set all of the signal lines active low by clicking on the Set On for each channel. On the screen, there should be an indication that the signal is active. 3. Verify Signal Verify that...

Fluke Daq Dio Relay Fuse Test

Open Communication Dialog Use the Communication dialog in Fluke DAQ for this test. Click on the DIO module icon in the TreeView display to see the DIO settings. The DIO dialog will only work if the DIO module is installed in the device and has been inserted using the Configuration dialog. Use the relay settings capability shown in the dialog to control the relays. 2. Set Each Relay Pair Set each relay pair. R 1 corresponds to the DIO relays K1A K1B. 3. Verify Relays Close Verify that relays...

Fluke DAQ Totalizer Count and Direction Test

Configure DIO In the Configuration dialog, select the DIO from TreeView. In the DIO Configuration dialog, set the start count to 0, deselect debounce (if selected), and select direction as down. 2. Start Spy Go to the Spy and start the Spy with the play button. 3. Verify Totalizer Value Verify that the totalizer value is has not changed. 4. Set Signal Generator Set the signal generator to 10 Hz and 1 V pp and connect to the totalizer input. 5. Verify Totalizer Count Verify that the totalizer...

Fluke DAQ Totalizer Count and Enable Test

Select DIO Click on the Communication icon and select the DIO from the TreeView. 2. Disable Totalizer Select the DIO channel 0 to disable the totalizer. 3. Start Spy Go to the Spy and start the Spy with the play button. 4. Verify Totalizer Value Verify that the totalizer value has not changed. 5. Set Signal Generator Set the signal generator to 10 Hz and 1 V pp and connect to the totalizer input. 6. Verify Totalizer Count Verify that the totalizer count does not change. 8. Disconnect Signal...

Fluke DAQ Totalizer Count Test

Go to Spy Window Go to the Spy Window. 2. Set Device Number Set the device number to the BCN number of the device and set the category as totalizer. 3. Start Spy Start the Spy with the play button. 4. Verify Totalizer Value Verify that the totalizer value is set to zero. 5. Set Signal Generator Set the signal generator to 10 Hz and 1 V pp and connect to the totalizer input. 6. Verify Totalizer Count Verify that the totalizer count increases by about 10 counts per second in a positive direction....

Fluke DAQ Trigger Input Test

Configure Trigger Input Using the Fluke DAQ software, configure the scan parameters for External Trigger with an Interval 2 of 1 second. Be sure Interval Trigger and Alarm Trigger are not enabled. 2. Verify Configuration Channel 1 for V dc In Fluke DAQ, verify channel 1 is configured for V dc, 3 V range. 3. Start Device Scanning Click the Start arrow in the Communication dialog to start device scanning, although no measurement scanning takes place because the external Trigger Input is not set....

Frequency

There are actually two parts to a frequency measurement. First, a normal V ac measurement is taken using the highest range. You must do this to determine the amplitude of the input signal, and thus the most appropriate gain setting to use for the actual frequency measurement. The frequency measurement circuitry works best with a large amplitude input signal. Therefore, the gain setting used is one higher than would be used for a normal V ac measurement. For example, if the autosensitivity...

Frequency Calibration Procedure

The Frequency calibration procedure calculates a calibration constant that corrects for errors in the frequency counter crystal frequency. It is sufficiently accurate to measure a single frequency point and calculate the scale factor assuming that the other endpoint is 0 Hz. Complete the following procedure to manually calibrate the frequency function. 1. If you have not already done so, complete the procedure Preparing for Calibration earlier in this chapter. 2. Connect the device and 5700A...

Function Relays

There are three relays (K25, K26, and K27) that route the signal to different portions of signal-conditioning circuitry on the A D board. These are relatively slow relays, requiring 6 ms to change position. Each relay has a SET and RESET position, which are configured by pulsing the SET and RESET coils, respectively. Each change of state of the function relays requires two writes by the A3U5 A D microprocessor one to set the appropriate bits and energize the relays and another to reset all the...

Inguard Digital Kernel Circuitry

The inguard digital kernel circuitry consists of devices A3U2, A3U5, A3U6, A3U7, and A3U10. The memory consists of Flash ROM (A3U6) that contains the internal A D program and RAM (A3U2). The 68302 microprocessor is A3U5, which communicates with the Controller System Power PCA, and the Stallion device via the serial lines SB CLK, SB XMIT, and SB RECV. Kernel communications are via the A D State Machine (FPGA IC, A3U18) using serial lines SB CLK, SB XMIT, and SB RECV (sends measurement commands...

Input Signal Conditioning

Each input is conditioned and or scaled to a dc voltage for measurement by the A D converter. DC voltage levels greater than 3 V are attenuated. To measure resistance, a dc current is applied across a series connection of the input resistance and a reference resistance to develop dc voltages that can be ratioed. DC volts and ohms measurements are filtered by a passive filter. AC voltages are first scaled by an ac buffer, converted to a representative dc voltage by an RMS converter, and then...

Integrate

The integrate state is when the input voltage is actually connected to the integrator. PREF and NREF are each switched off and on 10 to 20 times during this state and DREF is still off, INT is on, AZ is off, and the CMP signal is switching off and on. The primary signal is pin 7 of A3U19, which looks approximately like a triangular wave with 51.2 ms slope when the input voltage is zero. The triangular wave is very irregular at other voltages, moving on an upward or downward slope and reversing...

Introduction

The 268XA Service Manual supports the performance testing, calibration, servicing, and maintenance of the 2680A Data Acquisition System (DAS), the 2686A Data Logging System (DLS) and modules. See Figure 1-1 for a view of the 268XA. The 2686A comes with a removable PC Card (PCMCIA) for stand-alone storage operation. This socket accepts ATA memory cards up to 2 GB in size. Each 268XA device can hold from 1 to 6 analog modules. These modules are the Precision Analog module (PAI), Fast Analog...

Introduction and Specifications

Block 2680A 2686A Combined 2680A 2686A General Real-Time Clock and Trigger In Trigger Out Master Alarm Output Communication 2686A PC Card Precision Analog Input (PAI) A D Specifications PAI A D DC Voltage PAI A D AC Voltage Measurement PAI A D 4-Wire Resistance Measurement PAI A D 2-Wire Resistance Measurement PAI A D 4-Wire RTD per ITS-1990 Measurement PAI A D 2-Wire RTD per ITS-1990 Measurement PAI A D Thermocouple per ITS-1990 Measurement PAI A D Frequency Measurement Fast Analog Input (FAI)...

List of Tables

1-1. 268XA General 1-2. 268X Real-Time Clock and 1-3. Trigger In 1-4. Trigger Out 1-5. Master Alarm Output 1-6. 2686A - Active Channels and Number of Scans to Card 1-7. PAI A D DC Voltage General 1-8. PAI A D DC Voltage Range and Resolution 1-9. PAI A D DC Voltage Accuracy 1-10. PAI A D AC Voltage General 1-11. PAI A D AC Voltage Range and Resolution 1-12. PAI A D AC Voltage Accuracy 1-13. PAI A D 4-Wire Resistance Temperature 1-14. PAI A D 4 -Wire Resistance Range and Resolution 1-15. PAI A D...

Manual Calibration Commands

The calibration procedures are performed in the terminal mode using the commands CAL, CAL , CAL_REF, CAL_REF , CAL_STEP, and CAL_CLR. Refer to Table 5-2 for information regarding these commands. After each command is entered, the terminal returns one of three responses, as shown in Table 5-3. Start calibration of a new function, where x module slot number (1 to 6) and y an integer from 1 to 4. For example, CAL 1,1 to select module in slot one and V dc calibration. Return identifier of currently...

Manual Calibration Procedure

Manual calibration uses a calibration command set operated over an ASCII terminal or a computer running a terminal emulation program. The following procedure assumes you will be using the Windows Terminal feature of your host computer. If you are using a different terminal, adapt this procedure to suit. Complete the following procedure to prepare the Windows HyperTerminal feature. 1. Complete the Preparing for Calibration procedure earlier in this chapter. Note the device baud rate and host...

Master Alarm Output Specification

The following specifications cover the Master Alarm output. The Master Alarm output is located on the rear panel connector, terminals Master Alarm, and Signal GND. Table 1-5. Master Alarm Output Specification Table 1-5. Master Alarm Output Specification 0.8 V maximum for an Iout of -1.0 mA (1 LSTTL load) 3.8 V minimum for an Iout of 0.05 mA (1 LSTTL load) 3.25 V minimum for an Iout of -50 mA

Measurement Types

There are several steps that you must perform at the beginning of any channel measurement Set function relays. See Function Relays earlier in this chapter. This is a relatively slow operation and should be done only if the relay positions actually need to change. Set tree and channel switches. See Channel MUX earlier in this chapter. Program Stallion. See Stallion Chip and Signal Conditioning earlier in this chapter. Wait for channel switches to settle. See Table 2-10, Tree and Channel Switch...

Module Power Supply PCA 268XA4031

The module power supply PCA contains all of the analog side of the guard crossing hardware. It is located with each module's housing, as a daughter card that plugs into a 2 row, 10 pin header on the module. The power supply design uses a fully isolated push-pull topology, driven from a differential 393 kHz clock source. There are 3 regulated outputs that power the in-guard system +5.2 V (Vdd), -5.2 V (Vss) and +5.6 V (Vddr), each one is derived from a dedicated linear low dropout regulator (U5,...

Note on DIO Relays Digital lines programming

Serial control for the individual DIO Relays or Digital lines is based on bit values. For the relays, the firmware decided that 1 is reset and 0 is set for the digital lines, 1 is high and 0 is low. Relay 1 DIO line 0 has bit value 2A0 1, Relay 2 DIO line 1 has bit value 2A1 2, Relay 3 DIO line 2 has bit value 2A2 4, , Relay 8 DIO line 7 has bit value 2A7 128, DIO line 19 has bit value 2A19 524,288. The arguments for RELAY or DIO are < mask> , < value> . To Set Relays 2 and 3, the...

Ohms and RTD Measurement Circuitry

Resistance measurements are made by sourcing dc current through the unknown resistor and measuring the resultant dc voltage (see Table 2-5). The current source consists of operational amplifier A3U31, FET A3Q19, and switches internal to the Stallion. Four-wire measurements use separate source and sense signal paths to the point of the unknown resistance. This technique eliminates lead wire resistance errors. Figure 2-7 shows a simplified signal path for an RTD four-wire measurement. Table 2-5....

Open Thermocouple Check

Under control of the inguard microprocessor, the open thermocouple check circuit applies a small ac signal to a thermocouple input before each measurement. If an excessive resistance is encountered, an open thermocouple input condition is reported. The following paragraphs briefly describe the major sections of the Input Connector PCA, which is the Universal Input Module used for connecting the analog inputs to the instrument.

Open Thermocouple Detector

To check for an open thermocouple input, the appropriate channel is selected with the function relays also set to the appropriate position, and the OTC circuitry is enabled. This is done by setting the OTC_EN bit high and turning on the OTC_CLK signal, with a frequency of 19.2 kHz. OTC_CLK is supplied by the A3U5 A D microprocessor in the form of the SCC3 baud rate generator (BRG3 pin). After 1.7 ms, the OTC bit is read to determine the status of the channel. A 1 represents an open...

Perform Scan

The Perform Command Packet tells the A D Converter Assembly to do the following Measure Channel Number if set. Return BR 1 Zero Offset if set. Return BR2 Zero Offset if set. Return BR3 Zero Offset if set. Return BR4 Zero Offset if set. Return Reference Junction Reading if set. Return Reference Balance (both references Return Reference Balance (both references Action Performed The Perform Scan command causes the inguard to measure each channel indicated. These channels must have been previously...

Perform Self Test

The Command Packet tells the A D to perform all self tests. Response Packets Returned always returns a single response packet. The Response Packet Format provides the following A D self-test result, pass or fail. Zero Offset self-test result, pass or fail. Reference Balance self-test result, pass or fail. Ohms Overload self-test result, pass or fail. Open Thermocouple self-test result, pass or fail.

Performance Verification

Configuring the Performance Test Initializing the Performance Test Accuracy Performance Master Alarm Output RS-232 Master Alarm Output Fluke DAQ Master Alarm Output Trigger Input RS-232 Trigger Input Fluke DAQ Trigger Input Trigger Output RS-232 Trigger Output Fluke DAQ Trigger Output Volts DC Accuracy Test (PAI Volts DC Accuracy Test (FAI Volts AC Accuracy Frequency Accuracy Analog Channel Integrity Open Thermocouple Response 2-Wire Resistance Accuracy Test (PAI) - 2-Wire Resistance Accuracy...

Precision Analog Input Pai Ad Specifications

This section includes specifications specific to the PAI A D instrument by measurement function. Specifications PAI A D DC Voltage Measurement The following tables provide PAI A D specifications for the dc voltage measurement function. Table 1-7. PAI A D DC Voltage General Specifications Table 1-7. PAI A D DC Voltage General Specifications 100 MW in parallel with 300 pF maximum for ranges < 3 V 10 MW in parallel with 100 pF maximum for ranges > 3 V 50 dB minimum at 50 Hz 60 Hz +0.1 , Slow...

Preparing for Calibration

Complete the following procedure to prepare for calibration. 1. Connect the device RS-232 serial port to a host computer COM serial port as shown in Figure 5-1. The RS cables used are standard null-modem cables (reversed transmit and receive lines) that may be ordered from Fluke. 2. Wire the Universal Input Module so the high and low inputs to channels 1 and 11 are externally available. In addition, a four-wire short must be applied to channels 2 and 12. (See Figure 5-2.) Plug the module into...

Real Time Clock and Calendar

The next table provides a summary of the battery powered real-time clock and calendar. Table 1-2. 268X Real-Time Clock and Calendar Table 1-2. 268X Real-Time Clock and Calendar 1 minute per month for 0 C to 50 C range > 5 unpowered device years for 20 C to 28 C (68 F to 82.4 F).

Reference Junction Temperature

A semiconductor junction is used to sense the temperature of the thermocouple input terminals. The resulting dc output voltage is proportional to the block temperature and is sent to the A D Converter PCA for measurement. A D Converter PCA Circuit Description The following paragraphs describe the operation of the circuits on the A3 A D Converter PCA. See Figure 2-5 for a block diagram. The PAI and FAI A D Converter PCAs are identical, except for physical signal switching, and both use the...

Relay Output Drivers

Since the 8 Relay Output Drivers are identical in design , the following example description references only the components that are used for the operation of K1. The output relays are latching relays and therefor must be set reset individually. The Microprocessor controls the state of the Digital Output Driver DO< 20> by setting the level of the output U4 Pin 67. When U4 Pin 67 is set high, the output of the open-collector Darlington driver (U10 Pin 10) sinks current through the K1 Set...

Resistance Calibration Procedure

The resistance calibration procedure calculates gain and offset calibration constants for all of the four-wire ohms ranges. The same calibration constants are used for the Complete the following procedure to manually calibrate the ohms function. 1. If you have not already done so, complete the procedure Preparing for Calibration earlier in this chapter. 2. Connect the device and 5700A Calibrator as shown in Figure 5-4. 3. Complete the sequence of manual steps shown in Table 5-6. The default...

Retrieving Error Codes using RS232

You can retrieve error codes from the device using the device rear-panel RS-232 port and an ASCII terminal, or PC running ASCII terminal emulation. Complete the following procedure to retrieve error codes from the device using an RS-232 connection. 1. Connect the device to a PC COM port and setup the RS-232 parameters and connection as described in the procedure Manual Calibration Procedure in Chapter 5. 2. Enter the command *TST to invoke the device selftest routine and return the result, or...

Return Boot Firmware Version

This Command Packet Format requests version number of the inguard boot firmware and always returns a single response packet. Response Packet Format The response consists of five ASCII characters (plus the checksum byte), in the form Bxxyy, where B indicates boot software, xx are the two digits of the major version number, and yy are the two digits of the minor version number (there is an implicit decimal point between the two). Note that constraining the bytes to be ASCII characters causes the...

Return Firmware Version

This Command Packet requests version number of the inguard firmware and always returns a single response packet. Response Packet Format The response consists of five ASCII characters (plus the checksum byte), in the form txxyy, where t is F for FFE (FAI) software and P for the PFE (PAI) xx are the two digits of the major version number, and yy are the two digits of the minor version number (there is an implicit decimal point between the two). Note that constraining the bytes to be ASCII...

RS232 Device Configuration Parameters

When CAL is shown in the 2680A 2686A display, it indicates that you are in the calibration mode. The device configuration parameters are set as listed in Table 5-1. Table 5-1. RS-232 Device Configuration for Calibration Procedures Table 5-1. RS-232 Device Configuration for Calibration Procedures Figure 5-3. Two-Wire Calibration Connection Figure 5-3. Two-Wire Calibration Connection

RS232 DIO Relay Fuse Test

Use the RS-232 command RELAY < mask> ,< value> command to verify operation of the relays. The mask should always be set to 255. The value can be set from 1 to 255 depending on the bit to be set. For example, to set the relay pair K1A K1B, send RELAY 1,0. To clear the relay pair, send RELAY 1,1. To set relay pair K8A K8B, send RELAY 128,0 and to clear the pair send RELAY 128,128. 1. Connect Test Leads to Digital IO Relays Remove the DIO Connector module from the DIO rear panel. Connect...

RS232 Totalizer Count and Debounce Test

Initialize Totalizer to 0 Initialize the totalizer to 0 with the TOTINIT command. 2. Set Totalizer to Up Count Set the totalizer to up count with debounce on with the TOTCFG 1,1 command. 3. Set DIO Set DIO 0 to 0 to enable the totalizer. 4. Set Signal Generator Set the signal generator to 1 kHz at 1 V pp. 5. Connect Signal Generator Connect the signal generator. 6. Verify Totalizer Count Verify that the totalizer stays at 0+ -1 count. 7. Disconnect Signal Generator Disconnect the signal...

RS232 Totalizer Count and Direction Test

Initialize Totalizer to 0 Initialize the totalizer to 0 with the TOTINIT command. 2. Set Totalizer to Down Count Set the totalizer to down count with the TOTCFG 0,0 command. 3. Set DIO Set DIO 0 to 0 to enable the totalizer. 4. Reconnect Signal Generator Reconnect the signal generator. 5. Verify Totalizer Count Verify that the totalizer counts from 0 to 4,294,967,295, and then down. 6. Disconnect Signal Generator Disconnect the signal generator.

RS232 Totalizer Count and Enable Test

The enable signal is a hardware signal that must be disabled with an externally connected signal level such as a short to ground) 1. Initialize Totalizer to 0 Initialize the totalizer to 0 with the TOTINIT command. 2. Set DIO Set DIO 0 to 1 (on) to disable the totalizer. 3. Reconnect Signal Generator Reconnect the signal generator. 4. Verify Totalizer Count Verify that the totalizer count stays at 0. 5. Disconnect Signal Generator Disconnect the signal generator.

RS232 Totalizer Count Test

Initialize Totalizer to Count Up Initialize the totalizer to count up with the command TOTCFG < direction> ,< debounce> , where direction is 1 for up and debounce is 0 for off. 2. Initialize Totalizer to 0 Initialize the totalizer to 0 with the TOTINIT command. 3. Read the Totalizer Value Read the totalizer value with the TOT command. The value should be zero. 4. Set DIO Set DIO 0 to 0 (off) which will enable the totalizer to count. 5. Set the Generator Set the generator to 10 Hz and 1...

Schematics

Controller System Power 8-3. Digital I O 8-4. Backplane Extender 8-5. Extender 8-6. A D Supply 8-7. PCMCIA 8-8. Output 8-9. A D (PFE) 8-10. A D (FFE) 8-11. Analog Input Connector 8-12. Display subject to damage by STATIC ELECTRICITY clflCHt 'gl.lO TPla 200 SUBJECT TO DAMAGE Br STATIC ELECTRICITY SPI DRIVERS AND CONNECTOR FOR THE VACUUM FLOURESCENT DISPLAY AND CALIBRATION EEPROMS BUFFERS AND PROTECTION FOR EXTERNAL TRIGGER IN AND OUT AND MASTER ALARM OUTPUT

Selecting the Diagnostic Tools

This section describes the device diagnostic tool menu and other diagnostic features. The diagnostic tool menu is hidden from the user. There are three separate diagnostic tools that can be selected from the menu, each of which is described below. Complete the following procedure to select the diagnostic tools. 1. Power the device and allow it to complete the normal power-on sequence. 2. Press and hold the I pip key for 3 seconds until tool appears in the secondary display. Note that if you do...

Set Channel Configuration

The Command Packet tells the A D the following Measurement Function V dc, V ac, 2-Wire Ohms, 4-Wire Ohms, Frequency, Thermocouple, OFF. Range 90 mV or 300 W, 300 mV or 3 kW, 3 V or 30 kW, 30 V or 300 kW, 50 V (FAI), 150 300 V (PAI), or 3 MW, 750 mV (reference junction calibration). The range field is ignored for frequency and thermocouple channels. Channel Number 0 to 19 (though user sees channel 1 to 20) Enable Autorange if bit set (ignored for frequency and thermocouple). Enable Open...

Set Global Configuration

The Command Packet tells the A D the following Measurement Rate, fast, medium, or slow Power Line Frequency, 50 Hz or 60 Hz Scheduled Housekeeping Measurements, Enable or Disable Action Performed Sets global configuration parameters (instrument measurement rate, AC power line frequency, and enable or disable housekeeping measurements). The default state for the inguard is to measure on the fast rate, assuming 60 Hz, and with scheduled housekeeping measurements enabled. The meaning of scheduled...

Stallion Chip

The Stallion IC (A3U30) is a Fluke-designed 100-pin CMOS device that performs the following functions under control of the A D microprocessor (A3U5) A D buffer amplifier range switching Active filtering of ac voltage measurements The Stallion IC design is taken from the NetDAQ design and contains the A D conversion function using a multi-slope technique. Two separate signal paths are used. One path is for the functions dcv ohms temperature, and other path is used for ac voltages frequency.

Stallion Chip and Signal Conditioning

The Stallion Chip (A3U30) is a Fluke-custom IC that contains assorted switches, amplifiers, and the frequency counter. The chip contains registers that the A3U5 A D microprocessor may read and write to configure the chip and obtain frequency readings. Its interface to the A3U5 A D microprocessor consists of a synchronous serial port. The SCP port of the A3U5 A D microprocessor is used to program the Stallion, with a clock rate of 3.072 MHz. When reading information from the Stallion (the only...

T

C116 C12 1 C12 2 C12 3 C12 4 C12 5 C12 6 C12 7 C12 9 C13 1 C o.o1U o.o1U o.o1U o.o1U 0-01U o.o1U o.o1U o.o1U o.o1U 0.01U y c uuuuuuooooo - - - - - -> > > > > > -CEO RDY BSY CONF_DONE INIT_DONE -STATUS REMOVE R21 AND INSTALL W5 DATA0 (8)R21 IF EPC2 IS USED DATA1 (9) DATA2 (10) DATA3 (11) DATA4 (12) DATA5 (13) DATA6 (14) DATA7 (15)

Theory of Operation

Main Power Secondary Out-Guard Other Bus Serial Trigger In Out, Master PCMCIA Interface PCA Backplane PCA Display Module Module Power Supply PCA Digital Input Output Data Input Digital Input Digital Output Relay Output Totalizer Totalizer A D Theory of A D Converter PCA Block Analog Measurement Input Input Signal Analog-to-Digital (a d) Inguard Channel Open Thermocouple Analog Input PCA Block 20-Channel Reference Junction A D Converter PCA Circuit Stallion Input Input Signal Function Channel...

Thermocouples

A thermocouple channel is measured in the same way as a V dc channel, on the 90 mV range. However, before deselecting the channel at the end of the measurement, an open-thermocouple check may be done, if the channel is so configured. An open indication from this check causes a value of OTC_VAL to be returned for the channel measurement, regardless of the voltage measured. See Open-Thermocouple Detector. Thermocouple readings also require an isothermal block reference junction reading to be...

To avoid electric shock disconnect all channel inputs from the device before performing any troubleshooting operations

The Display Controller reads the DTEST* and LTE* inputs to determine how to initialize the display memory. DTEST* and LTE* default to logic 1 and logic 0, respectively, to cause all display segments to be initialized to on. DTEST* is connected to test points A2TP4, and LTE* is connected to A2TP5. Either test point can be jumpered to VCC (A2TP6) or GND (A2TP3) to select other display initialization patterns. Display Test Patterns 1 and 2 are a mixture of on and off segments with a recognizable...

Totalizer Input

The Totalizer Debounce circuit in the PLD (U3) allows the micro controller to select totaling either the input signal or the debounced input signal. The buffered Totalizer Input signal (TOT_IN) goes into the PLD at U3 Pin 13. U3 Pin 9 is the debounce enable control signal. It is active high ( HI Totalizer Debounced, Lo Totalizer NOT Debounced). The Totalizer output from the PLD is on U3 Pin 23 and this signal goes to the micro controller (CIN U4 Pin 2). The PLD receives its clock from the micro...

Totalizer Tests

The totalizer tests check the correct operation of the totalizer including the direction of counting and the signal level sensitivity. These tests can be run either with RS-232 commands or using Fluke DAQ. For these tests, use the signal generator to generate the counts. The generator will be connected to the totalizer input signal line (S). Connect the DIO channel 0 signal line to the totalizer enable line Sen) in the connector module. If you are using Fluke DAQ to perform the totalizer tests,...

Trigger Out Specifications

The next table provides a summary of the Trigger Out specifications. The Trigger Out output is located on the rear panel connector, terminals Trigger Out and Signal GND. Table 1-4. Trigger Out Specification Table 1-4. Trigger Out Specification 0.8 V maximum for an lout of -1.0 mA (1 LSTTL load) TTL Logical One - Trigger Out Not Set 3.8 V minimum for an lout of 0.05 mA (1 LSTTL load) Non-TTL Logical Zero - Trigger Out Set Non-TTL Logical One - Trigger Out Not Set 3.25 V minimum for an lout of...

Troubleshooting Calibration Failures

The paragraphs in this section describe troubleshooting actions when there is a calibration failure. Calibration of the device through the computer interface is described in Chapter 5 of this manual. Generally, a calibration failure is indicated by a Device Dependent Error and a > prompt after a CAL_STEP command. These indications occur if the analog input varies from what the device expects to see by more than + -5 or + -15 , depending on the calibration step. Before suspecting a fault with...

Troubleshooting the Device

The following paragraphs describe an organized method of device troubleshooting. The overall approach is to start with power-up self-test error codes and then proceed too increasingly detailed procedures. Begin troubleshooting with General Troubleshooting. These procedures locate about 90 of the device faults. The remaining faults require sleuthing that is beyond the scope of this manual. For these cases, review Chapter 2 Theory of Operation and approach the difficulty in a logical manner...

Troubleshooting the Keypad Master Alarm Output Trigger Input and Trigger Out Lines

When the device is powered, the U25 Field Programmable Gate Array is programmed by the contents of the flash ROM U9 as part of the initialization routine. Thus programmed, the FPGA interfaces with the keys portion of the A2 Display PCA and the backplane communication bus for every module slot. Check that the backplane is plugged snugly into the SYS CTRL card and the display cable is securely connected to the backplane card. U25 controls the rear panel master alarm output, trigger output, and...

Troubleshooting the Power Supply

To troubleshoot the power supply circuits, check each voltage, proceeding from the raw dc supply through the 5 V switcher and subsequent regulator circuits. If one of the supplies is folded back due to excessive current draw, remove PCBs from the SYS CTRL card to see if this unloads the power supply. If this works, then troubleshoot the bad board. When tracking down power supply loads, use a sensitive voltmeter and look for resistive drops across filter chokes, low value decoupling resistors,...

Troubleshooting the Sys Ctrl PCA Digital Kernel

The processor on the SYS CTRL card is a MPC855T packaged in a ball grid array. Its pin are unreachable for trouble shooting. Consequently, all references to signal pins will be the peripheral components. When the device is first powered, the resident RAM portion of the SYS CTRL microprocessor begins to initialize the digital kernel. This activity may be monitored at one of the SYS CTRL microprocessor chip select outputs, for example, CS1* at U18-21. If there is brief chip-select activity and...

DC Calibration Procedure

The V dc calibration procedure calculates gain and offset calibration constants for all of the V dc ranges. The 750 mV range is not user accessible, but is used to measure the reference junction voltage and must be calibrated. Complete the following procedure to manually calibrate the V dc function. 1. If you have not already done so, complete the procedure Preparing for Calibration earlier in this chapter. 2. Connect the device and 5700A Calibrator as shown in Figure 5-3. 3. Complete the...

Variations in the Display

Under normal operation, the display presents various combinations of brightly and dimly lit annunciators and digits. However, you may encounter other, random irregularities across different areas of the display under the following circumstances After prolonged periods of displaying the same information. If the display has not been used for a prolonged period. This phenomenon can be cleared by activating the entire display and leaving it on overnight (or at least for several hours). Use the...

Vdc Fast Rate FAI

Volts DC on the FAI, fast rate represent a special case. To attain the required throughput, you cannot perform the sequence of steps given above for each channel. Instead, certain characteristics of V dc readings are exploited in order to allow the A D to be triggered continuously for all the channels in a V dc block. A V dc block consists of a series of channels that are all defined as V dc, with similar ranges. Similar range means either the low ranges (90 mV, 300 mV, 750 mV, and 3 V) or the...

Voltage Reference Circuit

The voltage reference circuit creates a well-regulated +3.45 -3.45 V dc source for use by the A D converter, and as a source for ohms and current measurements. The circuit is formed around two dual op-amps A3U12 and A3U20. A3U12 controls balance between +3.45 V dc and -3.45 V dc by adjusting the +3.45 V dc through A3Q2 as the divider between these voltages in resistor pack A3Z1 reads above or below zero. The other half of A3U12 adjusts the absolute voltage difference between the two outputs by...