Posted 15 Apr 2017 (edited) Hello all, We are working on a traceability system that includes one machine with an omrom cpu with modbus tcp. The manufacturer of the machine send us the protocol of communications and everything works fine until there are any communication problems. Once these problems arise it is imposible to restablish the tcp communications between the PLC and the supervisor PC. The only way is shutting down the machine and power it on again (restart). It seems that the system only allows one tcp connection and it hangs up for some reason. Is there away to reset modbus communications without powering down the machine? Thanks a lot. Edited 15 Apr 2017 by mtecdm Share this post Link to post Share on other sites
Posted 20 Apr 2017 I don't know how you would do it over the network connection if that is down, but there is a system bit inside the PLC which can be used to restart each special function module, which basically reboots the one card. What the address is depends on the unit number on the special module. They are documented in the controller manual. For special IO modules, they start at A50200. For CPU bus modules, I don't know what the address is, if there is one. Share this post Link to post Share on other sites
