#MODBUS POLL TRANSACTION ID ERROR SERIAL#

#MODBUS POLL TRANSACTION ID ERROR SERIAL#

Serial comm has no transaction id though matching can only be done on the slave id and the message type (in this case write-holding-register). For I/P comm the transaction id is part of this key, so the two can typically be reliably matched. A 'waiting room key' is used to match up waiting requests with their responses. The explanation is a bit esoteric, so i'll give you the solution first: replace your seroUtils.jar file with the attached and restart Mango.ДЄll requests that expect responses go into a 'waiting room' while they wait for the thread that listens for reply data to provide the response. I have communicated with other PLCs and software to the same slaves before without any issues. I'm not sure what I need to do to relsove this. the 3 lines I have bolded look like where mango didn't get a response. The data source is set for a 500 ms time out and 2 retrys. I have the data point set up as settable and am toggling it from 0 to 1 back and forth and after a few toggels I get the error. For a simple experiment I have mango pulling one holding register every 5 seconds from the salve. It is when I am also writing to them that I get the error. Already contains the key do not get errors if I'm only reading from the slave. 'mainbox': Exception from modbus master: No recipient was found waiting for response for key Plug3: : Waiting room too crowded.

I'm starting to use Mango with a USB to serial adapter to read two Modbus slaves.

Modbus poll transaction id error