Communication between S7-1200 and Danfoss FC302 - How to setup more than one drive and how to set the commands, speed, etc.

Hello,

browsing for information I found your example.

I need to control several Danfoss FC 302 drives already wired for Modbus RTU communication.

I am thinking to use a S7-1200 PLC and I found your example very interesting.

I was wondring if you can share a working example where is possible to understand how to setup more than one drive and how to set the commands, speed, etc.. 

Thanks

Max

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Split from communication between S7-1200 and Danfoss FC302 using RS485.

Hi Maxi2570

Here is another example.

Regards, Ola

Hello, 

im trying to tweak your code, but im stuck with all the 32bit Values. i cant get them to be displayed correctly on VLT drive. Reference, Setpoint etc.

is there some special settings for this type of data, it seems that they should be arranged in "Danfos"way. 

Oh, and yes, im not very familiar with Modbus protocol.

Hi

What device you are communication with? Is it the same Danfoss device?

You may try to apply the methods bellow on the values you read:
#value2 := ROR(IN := #value1, N := 16);
#value2 := SWAP(#value1);

Kind regards

For users reading this post in the future, I recommend using the latest version of the library, it may be downloaded here: https://github.com/rexhip/rexhip/releases

Hi Ola,

problem with this particular Register is that it has inverse word order:

and i really dont know how to implement this in Siemens rtu setup.

Hi Korro

What I can see in your attachment is big endian, the most significant byte is frist in the first register. So you shouldn't need to swap any bytes. However you may try one of the following:

Updated version attached with a few improvements. 

Latest version will always be available at: 
github.com/rexhip/rexhip/

Kind regards