PLC-5 MSG Instruction .TO bit

I am currently having problems with MSG instruction taking up to 2 minutes on occasion transmitting 10 words of data between PLC-5s. The data passes from 1 DH+ to another via a DHRIO module. The MSG instruction is configured as a PLC-5 Typed Write.

I thought about using the .TO bit to abort the transfer, but when this is implemented the MSG block does go into error (as it should)and then re-sends when requested. However, despite aborting the transfer ALL of the data has been transferred successfully anyway - so what is the hold-up for?

Could the sending PLC be waiting for an ACK from the receiving one and if so is this likely to be because its bust either sending messages of its own or unable to obtain the token?

Any ideas anyone

Steve,

I don't know for sure, but it seems that if the message arrived even though you aborted it, then it must have been sent several times, and only got aborted AFTER a successful transmission.

Indeed the two PLCs must talk back and forth with ACK, and when you abort you must somehow convey the abort to the second PLC. Otherwise it is unaware.