OF and Modbus

Hi All

I’m working on a project which requires me to communicate with a plotting machine via a Trio motion controller. I need to communicate with it using the Modbus protocol using TCP/IP. I’ve managed to connect 2 OF applications on separate machines using ofxTCPManager but I’m having trouble connecting to Modbus Poll (a Modbus master simulator).

Does anyone have any experience in connecting to these technologies using OF? A Google search proved fruitless.



Modbus Poll is running on a PC (Win7). The OF app is v0.07 and is running on a Mac (osx 10.6). I’m trying to connect on port 502 as required by Modbus.

OF appends a delimiter string to any string based message being sent with send() - did you try sendRaw or sendRawBytes ?

Hi james, is it a ascii based protocol or binary? I’ve done lots of network programming and may e can help you if i get some more info. Greetz diederick

@Theo, thanks for your suggestion. I tried it but no joy.

@Diederick, there is an ASCII version of the protocol. We’re now looking to contract someone to help with this aspect of the project. We’re looking to get someone on 23-24th January. Are you available then? If so email me on - me[at]jamesalliban.co.uk and we’ll chat further.

Hi, just wondering if you guys had any luck w this? I may need to read and send simple modbus packets for an upcoming project. was hoping just to use OF’s built in TCP functionality without any other libs.