Posted 26 Aug 2023 Hi, After a long time, searching for missing communication I think to have found the cause. In this CMP2A plc there is a receiving device connected to the RS-232 port. . During operation it can happen that in the same cycle there will be 2 functions to send different data.. I never receive those 2 data, only 1 is received. I can set a delay for sending this but this seems to be 'overkill', Is there a simpler way to do this..? The 2 pics are part of the program. After putting the P_off before the other transmits, I always receive the TXD(48) DM1621... Please advise, Share this post Link to post Share on other sites
Posted 28 Aug 2023 You don’t need to set a delay necessarily (although a small one won’t hurt), but check/wait for the port to be not busy/InUse 2 people like this Share this post Link to post Share on other sites
