Michielvh1

modbus FX3U-485ADP-MB Problem need help

6 posts in this topic

Posted (edited)

I have got a FX3U-16M and -32M PLC and trying to connect with Moxa NPort 5130A serial device server to work with a scada.  It seems that i dont get the modbus to communicate.  I have tried the 110 ohm, 330 ohm and open setting on the device.  I am making use of a 2 wire system. I have configured both the channel 1 and channel 2 of the PLC to work with MODBUS 485.

i have written a program like follow

M8411    ----------- Move H1087 D8400

                 ----------- Move H1 D8401

                 ----------- Move K2000 D8409

                 ----------- Move K400 D8410

                 ----------- Move K10 D8411

                 ----------- Move K3 D8412

                 ----------- Move H1 D8415

                 ----------- Move K100 D8416

I just need to test if there is communication from these cards.  i have got 15 cards to test.

Any other help will also be appreciated.

Edited by Michielvh1
Updated the description

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Posted (edited)

I see D8401 is set to 1 modbus master RTU. 

Wouldn't SCADA be the master/Client  in this case ? If so set D8401 to H11 
You than should also set u the slave number in D8414

 

Modbus Slave program.JPG

Edited by Gambit

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i have changed it as you proposed.  i am testing the communication with Baseblock Com test and still it gives me an error: No Response received.   I can see that the RD light flickers red but nothing on the SD light.

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Posted (edited)

ok but who is sending the requests SCADA or the FX3U? Baseblock comtest is that scada or the moxa?

How is the serial comm parameters setup in the MOXA.

Did you reset the FX3U after implementing the change?

Edited by Gambit

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Posted (edited)

the request is coming from the PC.  The Scada will do the sending and requesting.  baseblock is just a modbus testing software that work with moxa.   The settings of the comms on the moxa is the same as i configured in the PLC.  I did clear the FX memory and reloaded the program

 

 

Edited by Michielvh1

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ok than the FX3U is the slave and should be H11. 
Can you post the settings of the moxa serial port and slave number 

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