Watlow CAS200 - Manual (Page 87)

CAS200 User’s Guide Chapter 5: Troubleshooting and Reconfiguring
Watlow Anafaze 75
Testing Output Devices
Connect the solid state relay (SSR) control terminals to the
CAS200 control output and connect a light bulb (or other
load that can easily be verified) to the output terminals on
the SSR. Put the channel in manual mode and set the
output to 100%. The ac load should turn on.
Do not attempt to measure ac voltage at the SSR’s output
terminals. Without a load connected, the SSR’s output
terminals do not turn off. This makes it difficult to
determine whether the SSR is actually working. Measure
the voltage across a load or use a load that can be visually
verified, such as a light bulb.
Testing the TB18 and TB50
1. Turn on power to the scanner.
2. Measure the +5Vdc supply at the TB18 or TB50. The
voltage should be +4.75 to +5.25 Vdc:
a) Connect the voltmeter’s common lead to the TB18
screw terminal 2 or TB50 screw terminal 3.
b) Connect the voltmeter’s positive lead to the TB18
or TB50 screw terminal 1.
Testing Digital Outputs
1. Turn off power to the scanner.
2. Disconnect any output wiring on the output to be test-
ed.
3. Connect a 500 Ω to 100kΩ resistor between the
+5V terminal (TB18 or TB50 screw terminal 1) and the
output terminal you want to test.
4. Connect the voltmeter’s common lead to the output
terminal, and connect the voltmeter’s positive lead to
the +5V terminal.
5. Restore power to the scanner.
6. If you are testing a digital output, use the MANUAL IO
TEST menu to turn the output on and off. See Manual
I/O Test on page 65. When the output is off, the output
voltage should be less than 1V. When the output is on,
the output voltage should be between +3.75 and
+5.25V.