Visilogic 570 and allen bradley powerflex 4 drive

[Rog]

I am kinda new to using visilogic and modbus. I just kinda need a better understanding of how to program using modbus to control this drive. Drive is allen bradley powerflex 4

Looking for a simple program to increase and decrease speed on the drive. Figuring on how the address part confuses me. Any example would help me understand little better

Thanks

 

[Joe Tauser]

Look at the existing Modbus examples to see how the function blocks go together.

It looks like you can talk to the drive using Modbus rtu via RS 485.  Look at this document starting on page C-2 - 

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/22a-um001_-en-e.pdf

Have you done any type of Modbus before?  It's not the simplest thing to do in Unitronics if you don't have a firm grasp on the Modbus protocol .  You may want to look at my post at the bottom of this thread:

http://forum.unitronics.com/topic/3582-modbus-rtu-and-danfoss/

Joe T.

[Rog]

1 hour ago, Joe Tauser said:

Look at the existing Modbus examples to see how the function blocks go together.

It looks like you can talk to the drive using Modbus rtu via RS 485.  Look at this document starting on page C-2 - 

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/22a-um001_-en-e.pdf

Have you done any type of Modbus before?  It's not the simplest thing to do in Unitronics if you don't have a firm grasp on the Modbus protocol .  You may want to look at my post at the bottom of this thread:

http://forum.unitronics.com/topic/3582-modbus-rtu-and-danfoss/

Joe T.

I have no knowledge of modbus. Besides watching the videos from Unitronics. Was wondering how the addresses are applied into the ladder logic. But I will look over, what you given me. 

[Flex727]

For MODBUS addressing, go to the Help file in VisiLogic, click on the Contents tab, then expand the following: Communications / Communications FBs / MODBUS, then select any of the topics you need to read up on. For addressing from an external MODBUS master, select Slave Addressing.

[John_R]

Rog,

attached is an example of MODBUS control of an AB Powerflex,.....

I cut this portion out of a program I did a year or so ago, parts of the logic may seem gibberish, like anything else , there are many ways to do the speed and/or run logic, but the key to the comms is is sending the right number to the right address, look at the parts where I send/receive with the MODBUS FB's.

I added some comments in CAPS, pointing out some things to pay attention to......

also remember, the port on the V570 must be set to 485....... and of course, the baud  in the com init, and node settings in the MODBUS FB have to match the VFD.......

Hope this helps.

Regards, JohnR

 

powerflex VFD example.vlp

[Rog]

27 minutes ago, JohnR said:

Rog,

attached is an example of MODBUS control of an AB Powerflex,.....

I cut this portion out of a program I did a year or so ago, parts of the logic may seem gibberish, like anything else , there are many ways to do the speed and/or run logic, but the key to the comms is is sending the right number to the right address, look at the parts where I send/receive with the MODBUS FB's.

I added some comments in CAPS, pointing out some things to pay attention to......

also remember, the port on the V570 must be set to 485....... and of course, the baud  in the com init, and node settings in the MODBUS FB have to match the VFD.......

Hope this helps.

Regards, JohnR

 

powerflex VFD example.vlp

Thanks. It does bring  in more perspective.