Rockwell Automation 1747-L5xx SLC 500 Modular Hardware Style User Manual - Manual (Page 157)

Publication 1747-UM011G-EN-P - June 2008
Troubleshooting 157
• Power status indicator is
on
• RS232 status indicator is
flashing
• FLT status indicator is off
or flashing
• Status of Run; Force;
DH-485, DH+, or ENET;
or Batt status indicators
do not matter
The processor is
trying to establish
communication,
but cannot find
other active nodes
DH-485
communication
parameters are set
up improperly.
1. Check communication parameters of programmer.
Programmer and processor communication rate must match.
Programmer and processor node addresses must be
different.
2. Try different combinations of:
a. communication rate (default is 19.2 K for DH-485)
b. node address (default is 1)
3. Try to increase the maximum node address. (default is 31 for
DH-485)
Bad connection of
communication
Device.
1. Check cable continuity.
2. Check cable connections between programmer and
processor.
3. Check communication device (for example, the 1747-PIC
interface). replace if necessary.
Low or no power to
communication
device.
1. Verify proper power supply selection and backplane loading.
(1747-PIC and 1747-AIC interface draw power off the
backplane.)
2. Verify proper 120/240V power supply jumper selection. See
page 106.
SLC 5/03. SLC 4/04, and SLC 5/05 Communication Errors
If the status indicators
indicate The following
error exists Probable Cause Recommended Action