Teledyne API Model 100AH SO2 Analyzer Instruction Manual, 02417, Rev. D
D. Use a DVM on each analog output channel to confirm the correct voltages.
If the voltages step, but are the wrong values, the V/F board may be out of calibration. See
Section 10.3.2.1 for information on how to calibrate the V/F board.
3. Digital input channel test.
The digital I/O section of the V/F board has 8 input bits and 24 output bits. Two of the 8
input bits are assigned as calibration controls. See Section 8.5 for information on calibration
using external contact closures.
To test the digital inputs:
A. Turn on the M100AH power on.
B. Connect a jumper wire across REMOTE IN terminals 1 and 2 of the rear panel connector
as shown in Figure 2-2.
C. Shortly after closure is made the instrument should switch into zero mode as indicated on
the front panel display.
D. Remove the jumper. Shortly after the jumper is removed the instrument should exit the
zero calibrate mode and enter the HOLDOFF mode. To exit the HOLDOFF mode press
EXIT, which will return the instrument to the SAMPLE mode.
4. Digital output channel test.
There are 24 output bits on the V/F board. The 24 bits are made up of three 8 bit ports. It is
possible for a single 8 bit port or even a single bit within a port to fail.
A quick observational test of the digital outputs is to observe the LED's in the Power Supply
Module (Refer to Figure 10-3 for the location of the LED's in the PSM). A more detailed test
is in the DIAGNOSTIC menu. See Diagnostic tests in Section 10.1.3.
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