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Jan 23, 2023 7:54 pm
Hey folks,
Looking to pass a data structure between two Beckhoff PLCs.
This is only intermittent data, as trays are passed between systems, so not occurring every scan.
Can see it's possible via either ADS or EAP.
EAP looks like a little more work, so preferring ADS.
Found examples here:
and here:
https://www.plccoder.com/communicating-between-beckhoff-controllers-part-2-ads/
But seems to rely on either a fixed offset in the PLC, or mapping to %MB areas and trying to avoid overlapping the addresses.
Is there a way to use symbolic comms, as is done from the ADS .Net library?
Thanks!
Duncan
2 Replies
Jan 24, 2023 2:50 am
@duncan this is possible. The two function blocks below use symbols instead of index/offset. 👍
FB_ReadAdsSymByName
FB_WriteAdsSymByName
Small example
PROGRAM MAIN VAR trigger : BOOL; adsWriteStatus : (IDLE, WRITE, BUSY, ERROR); adsWrite : FB_WriteAdsSymByName := ( sNetId := '192.168.0.2.1.1', nPort := 851, eComMode := E_AdsComMode.eAdsComModeSecureCom, tTimeout := DEFAULT_ADS_TIMEOUT ); sendTrayData : MyTrayStructure; END_VAR
CASE adsWriteStatus OF IDLE : IF trigger THEN trigger := FALSE; adsWriteStatus := WRITE; END_IF WRITE : adsWrite(bWrite := FALSE); adsWrite( sVarName := 'Main.receivedTrayData', nLen := SIZEOF(sendTrayData), nSrcAddr := ADR(sendTrayData), bWrite := TRUE ); adsWriteStatus := BUSY; BUSY : adsWrite(bWrite := FALSE); IF NOT adsWrite.bBusy THEN IF NOT adsWrite.bError THEN adsWriteStatus := IDLE; ELSE adsWriteStatus := ERROR; END_IF END_IF ERROR : // something went wrong... END_CASE
Jan 29, 2023 8:32 pm
