Send char data by Send_P2P FB from PtP Communication library

Hello,

wait! You say you sent some byte to CM so I expect in this case (also maybe if some PN network doesn't work as data exchange for CM to S7-300) that your CM must turn ON for a byte receive (only as signal pure electronic). If LED doesn't light try send more bytes as one message. I think your CM must turn LED on RX for data send from PC. If not, then something isn't correct with electric wiring, powere or something with cable probably. This is pure test that can show RX led on CM correctly, also with no data to S7-300 but LED must be ON for moment of receive message from PC, do this test only as HW check.

Hello,

ok, that's ok then. Really we need wait for Support answer but somehow still think about some other mechanism of data exchange, not only use of blocks. very similar situtaion I solved also with S7-1200 and ET200S PN IO module with 1SI Serial module where driver (blocks) isn't implemented but needed prepare it by my self  via PB DP I/O buffer. Ok, if you want next sugestion, no problem...

Hello,

next again I think about one important thing. You need definitelly use BYTE structure (Array is best) no other data type for send/recv data.

Hello,

very simple condition, if ERROR bit is true then MOVE -> STATUS to some free MW, then status can be visible at Online on this MW. Really not ok after long time and recommendation to do that checks in code 

Hello,

I expect you mean with SEND block, not from PC app in RECV block STATUS. You need look to Help about this block where STATUS values are described. Pls come here with that 2 STATUS code description.