Rockwell Automation 1771-QB Linear Pos. - Manual (Page 163)

Chapter
11
11Ć1
Troubleshooting
The module transfers diagnostic information to the programmable controller in
the status block. In addition, the module displays fault information for each loop
on the status indicators. Unless the module loses backplane power, all fault
conditions cause the fault indicator to turn on. Use the module’s indicators and
the status block to diagnose and remedy module faults and errors.
There are three indicators on the module front panel. (See Figure 11.1.) Monitor
them for the occurrence of faults.
Figure 11.1
Fault Indicators
50009
LINEAR
POSITIONING
FAULT
LOOP1
ACTIVE
LOOP2
ACTIVE
When you power up the module, all three indicators turn on for about one
second. Next, the LOOP 1 ACTIVE and LOOP 2 ACTIVE indicators turn off
while the module performs powerup diagnostics. If these diagnostics discover a
module fault, the red FAULT indicator remains on and the module remains
inactive.
After the successful completion of these diagnostics, all indicators go off. The
module won’t accept any loop parameters until after it detects power at each of
the external interfaces. This allows you to turn on the power supplies in any
order without generating loop faults. You can, however, still determine which
interfaces aren’t receiving power by reading loop 1’s analog, feedback, and
discrete fault bits in status word 2. (See Chapter 6.)
Fault Indicators