Modbus RTU control of Nanotec C5-E motor controller

[kl57]

I need to use commands for simple control of a stepper motor using a C5-E controller and Modbus RTU protocal. All I need is simple functions like, velocity, current, torque and position. I've never used  Modbus  in the past so I am having trouble getting started. I have a B & B USOPTL4 USB to RS485 converter. I 've downloaded the LV modbus libraries and set up the "Create Serial Master.vi" for new serial master and RTU. Nanotec has a document entitled "Functional-Description Plug Interface" that describes access #s for the different modes and settings. for example, to set the velocity operating mode, 

Step 1:  write 6060h:00h = 2h

Step 2:  write 6061h:00h (=2h?)

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Step n

I'm not sure which VIs to use or how to structure and write the commands.

Any assistance /direction  with this would be greatly appreciated

Thank you

[srpadmanaban]

Hi ,

were you able to establish the connection with Nanotec with Modbus, i am also currently working on this, i am not find the solution to run the motor with nanotec, i have used modbus for years but communicating with nanotec is not easy now

[rolfk]

From the OP's post it would seem to me that they use a very weird Modbus addressing syntax. Just as if the already existing ones wouldn't be already confusing enough, lets invent yet another one, since it is so much fun.

[tst]

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@rolfk wrote:

From the OP's post it would seem to me that they use a very weird Modbus addressing syntax.

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That's because it's EtherCAT. Specifically, the CiA402/DS402 profile, which deals with motion and defines those EtherCAT objects. I have no idea if and how this translates to Modbus in the Nanotec controller, but presumably the document mentioned in the first post refers to that.

[bego777]

You will use read/write holding register .vi. Read this document how to map CANopen objects to Modbus registers:

https://en.nanotec.com/fileadmin/files/Application_Notes/modbus-registers/ModbusRegisters_Applicatio...