Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
Teledyne Analytical Instruments 248
10.5.8.4. Status Outputs
The procedure below can be used to test the Status outputs:
1. Connect a jumper between the “D“ pin and the “” pin on the status output connector.
2. Connect a 1000 ohm resistor between the “+” pin and the pin for the status output that is being
tested.
3. Connect a voltmeter between the “” pin and the pin of the output being tested (see table below).
Under the DIAG SIGNAL I/O menu (See Section 10.1.3), scroll through the inputs and outputs until you
get to the output in question. Alternately turn on and off the output noting the voltage on the voltmeter, it
should vary between 0 volts for ON and 5 volts for OFF.
Table 10-12: Status Outputs Check
PIN (LEFT TO RIGHT) STATUS
1 SYSTEM OK
2 CONC VALID
3 HIGH RANGE
4 ZERO CAL
5 SPAN CAL
6 DIAG MODE
7 ALRM1
8 ALRM2
10.5.8.5. Control Inputs – Remote Zero, Span
The control input bits can be tested by the following procedure:
1. Connect a jumper from the +5 pin on the Status connector to the x5V on the Control In connector.
2. Connect a second jumper from the ‘-‘ pin on the Status connector to the A pin on the Control In
connector. The instrument should switch from SAMPLE mode to ZERO CAL R mode.
3. Connect a second jumper from the ‘-‘ pin on the Status connector to the B pin on the Control In
connector. The instrument should switch from SAMPLE mode to SPAN CAL R mode.
4. In each case, the GFC 7000TA should return to SAMPLE mode when the jumper is removed.
