Gabriel Franco Posted July 23, 2013 Report Share Posted July 23, 2013 More than a question, this post is to share an workaround I found. Visilogic 9.5.0 Modbus IP Master: V1210, using Socket 3, protocol UPD, port 502. Modbus IP Slaves: Two V130, one V280. Modbus IP time-out: #200 (2000 ms) Modbus IP retries: 3 V1210 reads registers (Function 03) then write registers (Function 16) to each slave, waits a delay time to communicate (Read and write) with next slave (Delay between slaves=0.1 s). After communicating with last slave, it waits a delay time (1.0 s) as a time between readings. Everything works as it should only if all slaves are up and running. If any of the slaves is off (Off or disconnected from Ethernet network), V1210 lost communication with all slaves (Time-out(4) then no communication (5) in status message). It´s only possible to recover communications with connected slaves if delay between slaves is greater than 3 seconds. So, I set proper timer preset value based on communication status with each slave: 0.1 s if OK, 3.0 s if failed. Quote Link to comment Share on other sites More sharing options...
sgull Posted July 23, 2013 Report Share Posted July 23, 2013 Hi Gabriel I think if you also set SB168 to on at power up it should recover the connection with the other slaves if you disconnect one even with the shorter delay. Would be nice to see if this works. Regards Denis Quote Link to comment Share on other sites More sharing options...
Ofir Posted July 23, 2013 Report Share Posted July 23, 2013 Hi Gabriel, Are you using UDP or TCP connection? As you have only three slaves, you can use TCP connection. In the masster set three sockets as TCP master (Each socket will have its own MODBUS Config) and connect to the slaves. In this configuration each slave is independent and if you will lose connection with one slave there will not be any delay with the others. Quote Link to comment Share on other sites More sharing options...
Gabriel Franco Posted July 23, 2013 Author Report Share Posted July 23, 2013 Denis, SB168 set at power-up in all devices from the begining. Ofir, I use UDP. I use a single socket for two main reasons: First, others are in use (Web server, PC communication, email), second: we expect to have more slaves in the near future. Quote Link to comment Share on other sites More sharing options...
Ofir Posted July 23, 2013 Report Share Posted July 23, 2013 Hi Gabriel, Please send us a mail to support@unitronics.com and I will send you examples for MODBUS over UDP. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.