Communication Errors - Allen-Bradley 1718 Ex I/O User Manual

Table of Contents

Advertisement

Communication errors

Table 8 - Communication errors
Error
Communication error on the fieldbus
Communication error on the service bus
Communication error on the service bus after successfully
establishing a connection
A new remote I/O unit will not work on a bus if other remote
FB I/O devices are already operating on the bus
The software cannot locate the adapter when establishing the
connection
Communication to the extension backplane is not possible
Bus-independent deactivation of the I/O modules is not
possible
Multiple I/O modules fail simultaneously
Troubleshoot Your Module
This chapter describes troubleshooting for RS-485-based bus systems.
WARNING: Risk of explosion
When work is performed on the remote I/O unit in hazardous areas, there is a
risk of explosion from spark formation.
Before starting any work on the remote I/O unit, familiarize yourself with the
instruction manuals for the components and their relevant certificates.
Remedy
• Check that the cables are connected.
• Check that the transmitting and receiving lines are wired correctly and have not been swapped.
• Check that the nodes are positioned in linear form and without branches. A star-shaped layout is not permitted.
• Check that the terminator has been activated. The fieldbus must have exactly two terminators per segment, one
at the beginning and one at the end.
• In the configuration software, check that the selected address is the same as the remote FB I/O device address.
• In the configuration software, check whether the master read cycle and the
with one another.
• Check that the cables are connected.
• Check that the nodes are positioned in linear form and without branches. A star-shaped layout is not permitted.
• Check that the terminator has been activated. The service bus must have exactly two terminators per segment,
one at the beginning and one at the end.
• In the configuration software, check that the selected address is the same as the remote FB I/O device address.
• Check that the correct interface is preset in the configuration software.
• Check that the service bus is galvanically isolated.
• If you are using a laptop, operate the laptop using a battery.
• Check the settings for the baud rate and transfer direction.
• Check that the terminators are still on the beginning and end of the bus after expansion.
• Check that the adapter is plugged in correctly.
• Check that the plug-in jumpers are set correctly.
• Check that the base backplane and the extension backplane are wired correctly.
• Check that the plug-in jumpers are set correctly.
• Check that the power supply is working properly.
• Check that the base backplane and the extension backplane are wired correctly.
Rockwell Automation Publication 1718-UM001A-EN-E - December 2019
A
Appendix
com unit watchdog
are coordinated
29

Advertisement

Table of Contents
loading

Table of Contents