Watlow PPC-2000 - Manual (Page 181)

PPC-2000 User’s Guide Chapter 4: Troubleshooting
Doc.# 30002-00 Rev 2.3 Watlow Anafaze 155
Communications
If communications has never worked, check the following:
• Is the PPC-2010 Processor running? The RX LED on the
port lights as the controller receives signals. The TX LED
lights if the controller receives a valid Modbus request.
This indicates a response being sent by the PPC.
• Is the communications cable in the correct connector on
the PPC-2010?
• Is the other wiring correct? See Connecting
Communication Ports on page 78.
• Is the RS-232/485 converter configured and working
properly? See Connecting Communication Ports on page
78 and the converter documentation.
• Are the communications parameters set the same in both
the PPC-2000 and the host device or software? See
Modbus Network Address on page 86.
• Is the host device or software configured properly? See the
appropriate user documentation.
• Is the correct communications port selected? See the
appropriate user documentation.
If communications was working and has failed, check these
things:
• Is the PPC-2010 Processor running? The RX LED on the
port lights as the controller receives signals. The TX LED
lights if the controller receives a valid Modbus request.
This indicates a response being sent by the PPC.
• Has the rotary switch setting on the Processor Module
been changed? See Modbus Network Address on page 86.
• Is the wiring correct? See Connecting Communication
Ports on page 78.
• Have any of the communications port settings on the
computer been changed? See the appropriate user
documentation.
• Is the RS-232/485 converter working properly?
If one of the programmable communications parameters may
have changed, establishing communications by following these
steps will demonstrate that all the components are functioning
and connections are correct: