Modbus TCP communication with Viewmarq LED sign

Does anybody use a Viewmarq led sign by Automationdirect with Ignition?

I have no luck trying to connect it using modbus tcp.

I have not, but their documentation is quite thorough. Where are you stuck, do you have a valid OPC device connection? Or do you have a valid connection but cant successfully write to your display?

A quick skim of the manual and i think they by default use unit id 255, in which case you would need to include it in your ignition Modbus addressing. Something like [deviceName]255.HRS11000

If you have any errors or configs you can share that will help also.

I have a good connection but am not able to figure out how to write to it. In their documentation, this how to write:

Blockquote
Command Strings are written to the ViewMarq Command String buffer starting at Modbus
Registers 411000 (up to 256 words).

I tried creating a tag [deviceName]1.HRUS11000 but when I insert a string it gives:
error

It looks like I have to write each character in the string to each modbus registers starting at 411000, not sure if this is what it is expecting.

That’s a tag config error, try changing zero based addressing option. You will get that for lots of reasons, like typing in a bad scan class name, device name, or an address out of bounds. If your 1/0 starting is wrong you could be accessing 10999 instead of 11000.

HRUS and HRS are not the same type. Did you mean to address just a single unsigned register?

Also, when addressing a String (HRS), a length is required at the end.

https://docs.inductiveautomation.com/display/DOC81/Modbus+Addressing

Thanks Kevin, i didnt know this, despite it being clearly stated in the manual as you indicated.

HRS FORMAT: HRS<Modbus address>:<length>