fail communication Modbus RTU in Labview

[luisiano]

Hello everyone ,

In my work, i have the order to change thePC Monitoring System (LabView). this reads and writes data a plc Micrologix 100 protocol 

Modbus RTU system and is sent trough moxa converter un over Ethernet, which has a software (nport administration) taht creates virtual ports on the PC in this case (com23) and this id recognized by  NI Visa and so I communicate with  Labview via Modbus RTU.

All Configuration but I did not work properly, because the new PC work fine until I remove the network cable from the old PC or turn it off, it`s like depended on the old PC to function well. not that I know but I feel that need to install anything or configure anything else on the new PC, but since it did, more than 3 years not work here can not ask for help, please welcome your answers and thanks for His time to reas this post.

Best regards 

[luisiano]

Hello everyone ,

In my work, i have the order to change thePC Monitoring System (LabView). this reads and writes data a plc Micrologix 100 protocol 

Modbus RTU system and is sent trough moxa converter un over Ethernet, which has a software (nport administration) taht creates virtual ports on the PC in this case (com23) and this id recognized by  NI Visa and so I communicate with  Labview via Modbus RTU.

All Configuration but I did not work properly, because the new PC work fine until I remove the network cable from the old PC or turn it off, it`s like depended on the old PC to function well. not that I know but I feel that need to install anything or configure anything else on the new PC, but since it did, more than 3 years not work here can not ask for help, please welcome your answers and thanks for His time to reas this post.

Best regards 

[Daikataro]

I'm guessing english is not your mother language, so please try to keep it simple and to the point. Here is some advice:

-Make sure your computer's IP is set to the same domain as your device, but different adress. For example if controller is 192.168.0.1 then set your PC IP to static 192.168.0.125 or anything else that isn't the last digit of the device

-If you couldn't communicate with the default LV I/O library, try the modbus library on this attachment: http://www.ni.com/example/29756/en/

-If you're using Serial Modbus, make sure details like baudrate, parity and handshaking are correct

-Ethernet Modbus is in my opinion, the best way if it's available, it is very straightforward. Make sure to keep speed low (5-7 read/writes per second) to avoid overloading your device with requests.

[luisiano]

thanks you,