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plcpeople / nodeS7

Node.JS library for communication to Siemens S7 PLCs
MIT License
356 stars 120 forks source link

Optimized block access #138

Open aferro17 opened 1 year ago

aferro17 commented 1 year ago

Hello @plcpeople,

Your project is amazing. I'm an Automation software developer and which mostly integrate SCADA, PLCs and some middleware software.

I was wondering if some S7 optimized block access reading and writing will be implemented instead of the old absolute address way. The feature you developed for having something similar on js side is awesome, but my collagues says (and also siemens) that havind dbs with absolute access slows down the cpu cycle.

Have a good one

plcpeople commented 1 year ago

There are no plans for this, because this is only supported with the new protocol which is still not documented either by Siemens or elsewhere on the internet. We have not found the speed effect of using absolute data blocks to be a problem for us in testing - I don't think the effect is large especially for a small number of blocks and I would suggest you run some tests to measure the effect. OPC UA is what Siemens supports for external access by an open protocol, and there is a node-opcua project that implements this.