Allen Bradley PanelView Modbus

  • Thread starter ali_alshaibani_iq
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ali_alshaibani_iq

I'm trying to build a project on PanelView C600 Touch Screen HMI. communicating it using Modbus with a pc via serial link. the pc act as a Modbus slave. after configuring both the slave simulating program and the HMI communication settings, I add a pushbutton command to the screen and linked it to a certain signal. when I run the project and press that command, the value of the register changed on the pc, but I got an error on the HMI saying "Write Error for Alias l63, Controller PLC-1, Address is 00001, Communication Flag is 0". looking at the messages, it seems like the pc receiving the message and send its response to HMI; same thing happened with reading and writing all other data types.

Hope any one can help solving this issue.
 
A

ali_alshaibani_iq

Thanks for reply, I've already tried to add delay time to slave response, that doesn't solve it.

>The slave in the PC may be responding BEFORE the PLC Host
>releases the RS485 lines.
 
Does the RS485 driver on the slave have an "Automatic Control Circuit" such as the B&B 485SD9R? Because typically the PC RTS Control is not precise enough for required Key Up Key Down timing.
 
Then you may have RS232 cabling issues such as no ground continuity.

>Thanks for reply, I'm using RS232, not 485.
 
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