Archive for the month of January 2012

Siemens Sirius 3RW44 Soft Starter Function Block for Step 7

Siemens Sirius 3RW44

Since I couldn't locate any examples to control a Siemens Sirius 3RW44 soft starter via Profibus DP in an S7-300 system using Step 7 — without PCS 7 or Soft Starter ES software — I decided to write my own reusable function block.

Since others may be running into the same problem, I decided to post the code here (project archive is attached). This allows communication over Profibus, which is far more advanced than reading and writing the standard 16 input/output bits.