ECR: Monitoring of the EtherCAT field bus

Document #:

LIGO-E1500401-v1

Document type:

E - Engineering documents

Abstract:

Currently, it is possible that part or all of the terminals connected through the EtherCAT bus are not operational without a clear error indication. We already have code to monitor each PLC and each task within a PLC, but we do not monitor the hardware bus itself.

This ECR proposes to add monitoring software to the TwinCAT system running on PLC1 which monitors the master bus device (i.e., the Ethernet interface). The following monitors would be added:
- A monitor for the working counters which check that each EtherCAT frame has successfully completed its round-trip though all addressed terminals.
- A status monitor indicating, if the master device is up and running.
- A status monitor indicating a link error (i.e., a cable got unhooked).
- A status monitor indicating, if one of the terminals is not in OP mode.
- A status monitor indicating, if the number of active terminals is different from the configuration (unexpected hardware change).
- A status monitor indicating a timing error.
- A status monitor indicating, if frames were lost.
- Statistics counters monitoring the EtherCAT frames.

Files in Document:

• E1500401-v1.pdf (151.1 kB)

Other Files:

• E1500401-v1.docm (26.8 kB)

Topics:

• State Control and Monitoring

Authors:

• Daniel Sigg
• Patrick Thomas

Notes and Changes:

This corresponds to issue tracker
https://services.ligo-wa.caltech.edu/integrationissues/show_bug.cgi?id=1131