The Industrial Raspberry Pi Forum

Hi Dirk and Kunbus Team,

We are considering purchasing several units from your site but I'm confused about what combination will work best for our application. We are developing a transmitter/HMI unit for our sensors and we are thinking to use your core and gateways in our transmitter that will be connected to external controllers. The transmitter should be able to do the following:
1. Our transmitter will be always in slave mode for the Modbus RTU protocol. Do you think we can use the RS-485 on the connect core and use that in a slave mode?
2. The transmitter will also be in slave mode for the Profibus protocol. Same question as 1. Should we consider buying an additional Profibus slave module? Do you think we can use the Rs-485 on the connect as the Modbus RTU port and add 1 gateway for the Profibus requirement?
3. How many gateways can we connect to the core or connect? In our case, we need to make sure we have provisions for Modbus RTU, Profibus, analog outputs (ideally 4 channels), analog inputs (ideally 4 channels), and 1 RJ 45 for OPC connection.

I look forward to your reply. Also, will it be possible to get the design/circuit diagrams for the Modbus RTU slave, Profibus slave, and analog I/O expansion modules?

Best,
Rohit

Hi Rohit, with interest I am reading your post. So this hardware configuarion is possible.
1- yes, you can use the RS485 on the front of the RevPi Connect+ in slave mode
have a look at the video tutorial Tutorial 23 – Modbus RTU Slave
2 - yesof course Profibus Slave Module is in the cart
3 - You may connect up to 5 IO Modules to the RevPi Connect and you may switch one of them to a Modular Gateway Module.
So an AIO Module can measure 4 input and 2 outputs with 16 bit resolution. Therefore you need two of them if you want to have 4 outputs.
You have two RJ45 ethernet interfaces which deals for i.e. OPC-UA or your so called shop-flor network and the cloud or IT network.
The schematics of some of the boards are in the Downloads section but the Modular Gateway Modules´ schematics are not public released.