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Technical support / Urgently need your help to solve Auto485 problem
« on: December 10, 2005, 11:03:47 PM »
Hi, I have a problem with auto485 card. Here is the senario:
In my project, 3 H-series (T44H) are used to control 24 cylinders. Inside each PLC, a program is burnt in to control the movements of cylinders. 3 PLC is coordinated by a Main PC. Through a Auto485 card, 3 RS485 linked PLC card connected to PC. The software we use to control PLC is C++, and the communication mode of Auto485 is set to RTS. However, when I power on my pc for the first time, I always got communication probelm with Auto485 card. When I tried to quiry the status of PLCs, the light and red indicator on Auto485 kept on blinking. I give u a example; I sent a commond "@01RI0000*" to PLC, the received data is like "RI0005A*". Since I am not getting the correct data, so my program will keep on looping until I got the correct data. Sometimes, i have to wait for 5 minutes to get a correct format response.
The Funny thing is: when I close my own program and turn on WINTriLogi 3.52 software and send out the same commond thru controller->serial port setup interface, I would get a message like "No response from PLC". So I close this WinTriLogi 3.52 software and turn on my own program to try again, amazingly, everything is working properly!! So I want to know in your WinTriLogi source code, what you have done to configure the serial port? In my program, the code was written properly to control RTS line, but why my program just can't work properly at start up? And only can work well after having tried WinTriLogi??
Answer from you is Urgently needed!
Thanks!!
In my project, 3 H-series (T44H) are used to control 24 cylinders. Inside each PLC, a program is burnt in to control the movements of cylinders. 3 PLC is coordinated by a Main PC. Through a Auto485 card, 3 RS485 linked PLC card connected to PC. The software we use to control PLC is C++, and the communication mode of Auto485 is set to RTS. However, when I power on my pc for the first time, I always got communication probelm with Auto485 card. When I tried to quiry the status of PLCs, the light and red indicator on Auto485 kept on blinking. I give u a example; I sent a commond "@01RI0000*" to PLC, the received data is like "RI0005A*". Since I am not getting the correct data, so my program will keep on looping until I got the correct data. Sometimes, i have to wait for 5 minutes to get a correct format response.
The Funny thing is: when I close my own program and turn on WINTriLogi 3.52 software and send out the same commond thru controller->serial port setup interface, I would get a message like "No response from PLC". So I close this WinTriLogi 3.52 software and turn on my own program to try again, amazingly, everything is working properly!! So I want to know in your WinTriLogi source code, what you have done to configure the serial port? In my program, the code was written properly to control RTS line, but why my program just can't work properly at start up? And only can work well after having tried WinTriLogi??
Answer from you is Urgently needed!
Thanks!!