Jump to content

UCR 8 communicating with V570 via Modbus RTU

Recommended Posts

Hello everyone, 

I have a UCR 8 which is connected to a V570 via serial. 

I am basically setting up Modbus RTU into the router to create a gateway between my Ethernet communication and the serial PLC.

I want to be able to remote access my controller via Remote Operator. It works fine with a V700 as it gets an Ethernet port, but It's been difficult  to get it running on a V570. 

Have you guys done this before?


Link to comment
Share on other sites

  • MVP 2014

Hi @VFU1076

I haven't done it but have discussed it with a customer.  The following youtube video explains the process well.  Just note that the video shows the connection using ethernet to the V570, and at that step you would set up the serial parameters instead.


Hope this helps,


Link to comment
Share on other sites

Hi Simon, 

Thanks for the input. I am not using the Unicloud service that Unitronics offers. Instead, I am using a third party DDNS service in order to be able to track what IP my controllers is getting assigned to it. 

There is a setup under services>rs232/485 into the router that needs to be configured in order to use the Remote Operator. I just don't know the exact settings needed. 

  My physical setup is : UCR>DB9-male to RJ11 male into Port 1 of the V570. 

In VisiLogic, I have a com port init in my power-up task to initialize the serial communication and same settings are being used into the router.

In Remote Operator, the ethernet call is my connection type where the router's IP is the target as well as its port. PLC name and everything seems to be correct, but I cannot access my controller.

Thank you.

Link to comment
Share on other sites


After lot of digging and chatting with an Engineer at Unitronics, it turns out that PCO, the protocol that Unitronics software uses to connect to PLCs is different when communicating over Ethernet and Serial. Over Ethernet, PCOM adds 6 bytes of data to the beginning of the message. Because of this, connecting from VisiLogic(over Ethernet) to the router and then forwarding that to the PLC via serial, the PLC does not recognize the command. 

A Serial to Etherner gateway software is necessary to accomplish this or through the UniCloud. I am still running some tests here and will let you know how that goes. 

Let me know if anyone knows a FREE serial to ethernet gateway software as I only found paid ones so far. 


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...