Greetings

I am currently testing different methods to send data between a PC and a S7-1200 PLC. But for some reason I can't seem to get the Data exchange via the TSEND_C block working.

The Connection is successfully established and recognized by my client program (Status 7004) but then it gets kinda Stuck there. Setting Start_Request REQ to true has not effect on the Status, DONE, BUSY and ERROR are always false, and no data is received on the PC.

For my Test I used this Guide:

http://www.infoplc.net/files/descargas/siemens/infoplc_net_the_guide_about_tcpip_connections_between_pcs_and_siemens_plcs.pdf

I copied the implementation pretty much step by step (I even used the exact same client program for my test). Just be sure im gonna add Screenshots of my TSEND_C configuration aswell. If you need any additional info please let me know.

I know this may very well be a Firewall issue, but Ive already allowed all used Ports through the Windows Firewall (I got the lmqtt library working that way, wich is tcp based too) So Im kinda out of Ideas.

Any Help is appreciated

Hello Kaulquappe, I hope i didnt misunderstand your suggestion

Yes I keep a close eye on the Outputs of TSEND_C on Step7. Error=False, Status = 7004 (no matter the state of REQ) until I either set CON=false or close my client program.

Edit: Checking Error=TRUE in code yields no different results

See my Edit.  Evaluating Error within the Program didn't detect any errors

Hello Kaulquappe,

yes I did set REQ with a "P_TRIG" Block (as it is done in the linked guide)

However, setting REQ from false to true manually is supposed to work as well (it work with lmqtt wich is triggered on positive edge aswell)

Hello again,

Apologies for the Late response, I didn't get to work on the Hardware. Checking Busy and Done programmatically and testing differed Length parameters made me realize the Block has been working all along, just fine.

Apparently I managed to use two Test clients in VB and Java which both successfully received Data from the PLC but failed to trigger any output at all to indicate that Fact .

Well, I can only blame my lack of knowledge in both languages and the TCP protocol altogether. Hopefully getting the TRCV_C to work with all the acquired info will be easier

Much Thanks for all the Help