Siemens Step 7 scan rate


Thread Starter


I am working on a project that invloves a 20-bit encoder that sends positioning coordinates to the PLC. Something that concerns me is the scan rate of the PLC. Can the PLC handle the 20-bit positioning coordinates? What is the can rate of a Siemens Step 7 PLC?


A PLC Programmer

SCAN Time Depends

1) From CPU type to Type
2) Yours Total Program Length

To calculate it just check a latest Siemens ST-70 Catalogue.

Siemens PLCs handle real time data for Positioning Encoders by their special dedicated Modules and Step-7 Dedicated Function Blocks.

You may have to use that module for yours application.

A PLC Programmer
The scan rate depens on which S7 plc family are you working, because exist S7-200, S7-300 and S7-400. Besides which CPU in the repetive family.

The important when you are working with encoder in the rate of bits (HZ) acording to the rate of reading for the i-o card are you using.

WE need more data to evaluate if you encoder can be use in your application