Siemens S7-300 slow response time

Ignition
1

Hi all,

We have a setup using 7.9.10 connecting to a Siemens 317fpn/dp on the PLC:s internal ethernet interface.
The PLC is configured to use 50% of the cpu for communication and the PLC scan cycle time is still below 10ms. So not much load on the PLC because of the plc program.

Twice a day almost on a daily basis we get slow response reading tags in ignition.
The issue remains for about 30 minutes and then it goes back to normal.

Bad response:

bad response
bad response1169×621 31.9 KB

Normal response:

image
image1156×624 31.2 KB

Any ideas?

2

Do you have some form of automatic PLC backup system that runs regularly? I would expect PLC programmer operations to create this sort of conflict. The open protocol Ignition uses has lower priority than programmer actions.

3

No, nothing else connects to the PLC.

4

Is there a way to log “Mean response time” or “Load factor”.
It would be great for troubleshooting, pinpoint the hours when the error occurs.