Instruction manual

Instruction Manual
760006-A
September 2001
11-12 Appendices Rosemount Analytical Inc. A Division of Emerson Process Management
Model NGA 2000 Platform
Analog I/O Module Relay Op-
eration Check
For troubleshooting, it is convenient to
check the measured state of the relays
when they don’t seem to be working.
The circuitry actually measures the un-
used contacts of the relays.
You can see what their state is, and you
can manually set them to a state:
1. Get into Technical level configura-
tion...
2. Select Diagnostic menus...
3. Select the I/O module
4. Select Relay status...
5. Set Relay function: to TEST. This
allows you to edit the relay states,
but it will automatically reset itself to
auto after a minute.
6. Look at each relay, and if desired
edit its status line to ON or OFF.
After a moment you should see its
measure line change state too.
Check to see if the reporting device
sees this. If not, you either have a
wiring error, or there is a failure in
the EMC circuitry or output connec-
tor.
NOTE
V2.2 I/O modules report the state of
relays 1, 2 and 3 reversed from reality -
that is to say they report the contact
open when it is in fact closed, and vice
versa.