Experimental Physics and
Industrial Control System

Hi all,

I am setting up an IOC to interface with a Control Logix 5000 PLC using the EtherIP EPICS support.

I’ve successfully set everything up and can read all but three tags from the PLC.

For the three tags that are not working, when I include them in the substitution file, I get an error displayed to the IOC shell every few seconds:

EIP connecting bleps

EIP process_ScanList: Error in response

< list of tags >

CIP_MultiRequest reply: invalid service 0x52

2020/01/14 14:14:34.5732 EIP disconnecting bleps

(‘bleps’ is the name of the PLC, and I’ve removed the list of PLC tags).

I’ve checked that the three tags which are causing the “invalid service” error exist and respond using the ether_ip_test utility, and all the tags can be queried using caget, so communication through the EtherIP support is successful.

The problem at hand is on my MEDM display screen, red/green ovals for bool-type alarm tags show as white (color mode is set to alarm), and their “Alarm” state is “INVALID”.

Simply not including the three tags that cause the problem alleviates the invalid alarm states, and the display works correctly.

I’ve found some info online stating CIP service code 0x52 is an Allen-Bradley proprietary “read tag fragmented service”; does the EtherIP support not support this service, and if this is the case, does anyone have experience reconfiguring the tags so they do not use this service?

Thanks!

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Roy Guerra

Pronouns: they, them, theirs

Beamline Controls and Data Acquisition, X-Ray Science Division, Advanced Photon Source