Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2
5-27
5.5. 4-20 mA Current Loop The analog signal output is available on the rear panel as a voltage or 4-20 mA current output.
Optionally the current loop outputs can be isolated. See Section 6.3 for a description of isolated
current loop outputs.
The current outputs come out on the same terminals that are used for voltage outputs see
Figure 2-2. The NO, NOx, NO2 and Test Channel outputs have current loop capabilities. See
Troubleshooting Section 9.3.4.4 for electrical specifications.
The factory default is voltage outputs. To convert from voltage to current loop, move the
jumpers on the motherboard from the default B-C (rear pins) position to the A-B (forward pins)
position. See the 01110 Motherboard schematic in the Appendix.
5.6. Status Output The status output is an option that reports Analyzer conditions via contact closures on the rear
panel. The closures are available on a 50 pin connector on the rear panel. The contacts are NPN
transistors which can pass 50 ma of direct current. The pin assignments are listed in Table 5-8.
Table 5-8: Status Output Pin Assignments
Output # Pin # Definition Condition
1 1,2 ZERO CAL CLOSED IN ZERO CAL
2 3,4 SPAN CAL CLOSED IN HIGH SPAN CALIBRATION
3 5,6 FLOW ALARM CLOSED IF FLOW WARNING
4 7,8 TEMP ALARM CLOSED IF ANY TEMP WARNING
5 9,10 DIAG MODE CLOSED IN DIAG MODE
6 11,12 POWER OK CLOSED IF SYSTEM POWER OK
7 13,14 CONC ALARM CLOSED IF CONCENTRATION
WARNING
8 27,28 LOW SPAN CAL CLOSED IN LOW SPAN CALIBRATION
9 SPARE
10 19,20 AUTORANGE - HI CLOSED IF IN HIGH RANGE
11 21,22 SYSTEM OK CLOSED IF NO FAULTS PRESENT
12 23,24 RX CELL PRESS CLOSED IF ABS PRES > 15" HG
The Status Board schematic can be found in the Appendix Drawing 01087.