How to determine PROFIBUS IO scan time
I have logged on to the AC800M Webserver and found a cycle time (see attached image). Will this be the IO scan time? I'm aware that some modules are only scanned every fourth or tenth cycle but is this the cycle time that is refered to?
It seems a bit fast when I compare to the ABB S800 I/O Product Guide 3BSE 015 969R301 Page 60-62.
The easiest way will be to use Profitrace and record the traffic, mark message request and message response from the slave you are interested in. and see the difference in time.
They cycle time you see in web browser is Measured Profibus cycle time, I think its the time it takes to scan whole Profibus. including token transfer, Cyclic and Acyclic message exchange with all slaves and master (if multimaster topology is used)
The calculation you see in the Product guide is the scan time for FCI towards I/O module and not between CI854 and FCI.