Siemens IM 153-4 PN, Руководство по эксплуатации

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Functions
8.6 Isochrone mode
ET 200M
170
Operating Instructions, 12/2008, EWA-4NEB780600602-08
Optimizing the equidistant time
● An optimization of the periods for the equidistant bus cycle can be achieved through the
correct plugging sequence of the I/O modules:
–
Plug the output modules with the longest processing time on the left in the ET 200M.
– Plug the input modules with the longest processing time on the right in the ET 200M.
Detailed information can be found in the technical data for the module concerned.
● The greatest delay (configurable) with the digital input / output modules essentially
determines the length of the equidistant DP cycle.
Tip: In isochrone mode, ensure the same delay on all digital modules in the ET 200M
station.
● The smaller the input delays are that you set for the digital input modules, the shorter the
possible equidistance times will be.
Tip: If possible, for the digital input modules set an input delay of 0.1 ms.
● In the case of modules which support clock synchronism, the processing time at the
module must also be taken into consideration.
● The achievable, minimum equidistant time in the station depends on the number of
modules in the ET 200M.
You can also achieve small equidistance times if you distribute the modules of an ET
200M (with a large number of modules) between two ET 200M stations.
● The equidistance time is reduced if you increase the transmission rate.
Tip: Set the greatest possible Baud rate.