Motherboard; A/D Functions; Analog Output Voltages - Teledyne T101 Operation Manual

Teledyne ML - T101 Operation Manual
Table 9-6. Relay Board Control Devices

9.5.9. MOTHERBOARD

9.5.9.1. A/D functions

9.5.9.2. Analog Output Voltages

Table 9-7. Analog Output Test Function - Nominal Values
STEP
1
2
does not turn on/off, then the associated device (valve or heater) or its control device
(valve driver, heater relay) is malfunctioning.
Several of the control devices are in sockets and can easily be replaced. The table below
lists the control device associated with a particular function:
FUNCTION
Valve0 – Valve3
Valve4 – Valve7
All heaters
A basic check of the analog to digital (A/D) converter operation on the motherboard is
to use the Signal I/O function under the DIAG menu. Check the following two A/D
reference voltages and input signals that can be easily measured with a voltmeter.
Using the Signal I/O function (Section 4.6.1 and Appendix D), view the
•
value of REF_4096_MV and REF_GND. If these signals are within 10
mV and 3 mV, respectively, of their nominal values (4096 and 0) and are
stable to within ±0.5 mV, the basic A/D converter is functioning properly.
If these values fluctuate largely or are off by more than specified above,
one or more of the analog circuits may be overloaded or the
motherboard may be faulty.
Choose one parameter in the Signal I/O function such as
•
SAMPLE_PRESSURE (see previous section on how to measure it).
Compare its actual voltage with the voltage displayed through the
SIGNAL I/O function. If the wiring is intact but there is a difference of
more than ±10 mV between the measured and displayed voltage, the
motherboard may be faulty.
To verify that the analog outputs are working properly, connect a voltmeter to the output
in question and perform an analog output step test as described in Section 4.6.2.
For each of the steps, taking into account any offset that may have been programmed
into the channel (Section 4.6.3.4), the output should be within 1% of the nominal value
listed in the table below except for the 0% step, which should be within 2-3 mV. If one
or more of the steps is outside of this range, a failure of one or both D/A converters and
their associated circuitry on the motherboard is likely.
100MV
%
0 0 mV
20 20 mV
CONTROL DEVICE
U5
U6
K1-K5
FULL SCALE OUTPUT VOLTAGE
1V
NOMINAL OUTPUT VOLTAGE
0
0.2
Troubleshooting & Service
SOCKETED
Yes
Yes
Yes
5V 10V
0 0
1 2
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