Troubleshooting, Stand alone systems, Checking control outputs – Watlow 8LS Controller User Manual
Page 93: Checking digital i/o

Troubleshooting
8LS User’s Guide 85
Troubleshooting
NOTE
If you need to return the 8LS to Watlow-Anafaze,
please call first for a Returned Materials Authori-
zation (RMA) number. This number helps us track
your equipment and return it to you as soon as
possible.
Stand Alone Systems
If the unit has no display, check the 120vac power supply.
If you insert a spare unit, enter the values from the original unit. You
can store and enter these values using a standard IBM PC or compatible
computer and ANASOFT software.
Checking Control Outputs
To check control outputs:
1. Set the loop you want to check to Manual mode.
2. Set the output power percentage to the desired level.
3. Set the output type to On, Off or TP.
A very simple test is to use a LED with a series 1K resistor connected
across a TP or DZC output to see if it’s pulsing. You can also use a
voltmeter to check the outputs.
Checking Digital I/O
Check the digital I/O from the Test I/O menu. You can also use a LED
with a series 1k resistor to see the outputs turn On and Off.