I've been working with Allen Bradley SLC-500's for years, never paying much attention to the spinning icon at the top of RSLogix 500 program. Now it seems I have a timing issue with a certain 1747-L532 CPU. The field guys are saying it runs too fast, but the icon rotates every 3 seconds or so and it keeps real time with the PC clock. I've seen icons spin much, much slower yet that action seems independent of keeping real time. Does anyone know how to slow the spinning icon down?

Many Thanks,

 

Hi,

From what I remember the spinning icon is an indication of the speed of comms between the PC and PLC. The faster the spinning the closer to real-time view of the ladder logic you get. It has nothing to do with the scan time.

I've slowed down the spinning icon by having lots of ladder files open online. Each one updates 'live' and slows the others down.

By reducing the number of ladder files open and being monitored, you can speed it up again and the apparent response of the PLC seems more lively.

Monitor S:23 in the CPU, this should remain stable as this is the real average scan time of an SLC.

Regards
Patrick