Watlow CPC400 - Manual (Page 165)

CPC400 Series User’s Guide Chapter 6: Troubleshooting and Reconfiguring
Doc. 0600-2900-2000 Watlow Anafaze 151
b) Connect the voltmeter’s positive lead to the TB18
or TB50 terminal 1.
Testing Control and Digital Outputs
1. Switch off power to the controller.
2. Disconnect any output wiring on the output to be test-
ed.
3. Connect a 500 Ω to 100 k Ω resistor between the
+5V terminal (TB18 or TB50 terminal 1) and the out-
put 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 controller.
6. If you are testing a control output, turn the output on
and off by setting the loop to 100 percent and 0 percent
output power (see Changing the Control Mode and
Output Power on page 55). When the output is off (0
percent), the output voltage should be less than 1V.
When the output is on (100 percent), the output volt-
age should be between +3.75 and +5.25V.
7. If you are testing a digital output not used for control,
use the I/O tests menu to turn the output on and off.
See Test Digital Output 1 to 35 on page 132.
Testing Digital Inputs
1. Switch off power to the controller.
2. Disconnect any system wiring from the input to be
tested.
3. Restore power to the controller.
4. Go to the Digital inputs parameter in the I/O tests
menu.
5. Attach a wire to the terminal of the digital input to
test. When the wire is connected only to the digital in-
put terminal, the Digital inputs parameter should
show that the input is off (0). When you connect the
other end of the wire to controller common (TB50 ter-
minal 3), the Digital inputs parameter should show
that the input is on (1).