Motherboard; A/D Functions; Analog Outputs Voltage; Figure 8-4. Analog Outputs Page - Teledyne T750 User Manual

M
OTHERBOARD

A/D Functions

The simplest method to check the operation of the A-to-D converter on the motherboard is
to use the Analog Inputs page in the Utilities>Diagnostics menu to check the two A/D
reference voltages and input signals that can be easily measured with a voltmeter.
1. Use the Analog Inputs function to view the value of Ref 4096mV and Ref Ground.
• If both are within 3 mV of nominal (4096 and 0), and are stable, ±0.5 mV then
• If not, then the motherboard is bad.
2. Choose an Analog Inputs function such as Diluent Pressure or Sample Flow, and
compare these voltages at their origin (see Interconnect drawing in Appendix B)
with the voltage displayed through the Utilities>Diagnostics>Analog Inputs
menu.
• If the wiring is intact but there is a large difference between the measured and

Analog Outputs Voltage

To verify that the analog output is working properly, connect a voltmeter to the analog
output in question and perform an analog output step test as follows:
1. Navigate to the Utilities>Diagnostics>Analog Outputs page
2. Use the Press to Set Output button to set the desired percent of the signal output in
the numeric keypad that pops up, and press Enter.
3. Compare the value displayed in the Analog Output field to the voltmeter.
For each percentage set, the output should be within 1% of the nominal value. Use the table
below as an example. Ensure to take into account any offset that may have been
programmed into the analog output channel.
083730750B DCN8606
the basic A/D is functioning properly. I
displayed voltage (±10 mV) then the motherboard is bad.

Figure 8-4. Analog Outputs Page

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