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MODBUS Issue with IAI Robocylinders

Hi

 

I am trying to send the following command using MODBUS protocol to IAI Robocylinders (ACON-C series)...I configure my COM port and send the correct HEX string correctly but the bytes at port always comes up with 0. Any explanation what could be causing this? The IAI software interface communicated perfectly well with the Robocylinders on the same COM port....so I know it is setup correctly....

But when I try to perform the same function through LabVIEW's MODBUS drivers, I get 0 bytes at port...

I am trying to send the following at 38400 baud rate, 8, None, 1, None using ASCII mode.... if I use RTU mode (and I format the Write string accordingly), the response is the same....

 

A sample query that turns the servo of a controller of axis No. 0 on is shown below.

Query: 01 05 04 03 FF 00 F4

Converted ASCII

 

3A 3031 3035 30343033 46463030 4634 0D0A

If the change is successful, the response message will be the same as the query.

 

This is where I do NOT get the same message back and the bytes at port is 0.

I am using LabVIEW 2011 on a Win 7 32 bit machine.

 

Care to explain?

 

Thanks.

Vishal

 

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Message 1 of 12
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Hey Vishal, 

 

Are you using your Modbus protocol through the LabVIEW DSC module or just the downloadable Modbus library from our website?

 

Thanks,

 

Doug B

Applications Engineer
National Instruments
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Message 2 of 12
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Download portmon from here, to record the serial data stream that comes out of the port. Compare this to the vendor software and the labview code.

 

http://technet.microsoft.com/en-us/sysinternals/bb896644

 

Or try Nispy.

 

http://www.ni.com/support/vxi/spy/spy.htm

 

 

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Message 3 of 12
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Hi

 

I have exactly the same problem. What was the failure? Have you got a working vi?

 

Thanks in advance!

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Message 4 of 12
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Hi,

 

Could you please be more specific? Are you using your Modbus protocol through the LabVIEW DSC module?

 

Regards,

Bobby Breyer
Applications Engineer
National Instruments
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Message 5 of 12
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Hi

I solved the problem by using another axis number than 0.

Best regards
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Message 6 of 12
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Hello,

 

I've got the same exact problem as you guys.

 

I tried communicating with my IAI ACON-SE with both the Labview DSC Module and the Modbus driver and i didnt revience any message back from the controller.

 

Do any of you guys have a working vi for communcating with the device?

 

Thanks.

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Message 7 of 12
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Hello

 

I produced a fully working driver with all functions, but I can't upload the VI.

 

Best regards

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Message 8 of 12
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Hello,

 

Why can't you upload the VI?

 

Is there any other way you could help me?

 

 

Thanks

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Message 9 of 12
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Hello

 

Please send me your email address and I can send the VI's to you.

 

Best regards

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Message 10 of 12
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