Main Ring Diagnostics

Diagnosing the Remote I/O Main Ring

You can monitor breaks in the by diagnosing the REDUNDANCY_STATUS bits in the 140CRP31200 remote I/O head module DDT. The system detects and reports in this bit a main ring cable break that persists for at least 5 seconds.

Within the REDUNDANCY_STATUS bit:

0 = cable is broken or device has stopped
1 = loop is present and healthy

In a Hot Standby system, perform a BITWISE OR operation of the REDUNDANCY_STATUS bit in the DDTs for both the primary and standby 140CRP31200 modules to determine whether a cable break has occurred. As indicated above, a value of 0 indicates a cable break; a value of 1 indicates no cable break.

NOTE: Refer to the Quantum EIO Remote I/O Modules Installation and Configuration Guide for a list of diagnostic status bits.

remote I/O main ring

The main ring of an Ethernet remote I/O network. The ring contains remote I/O devices and a local rack (containing a controller, a power supply module, and an Ethernet remote I/O head module).