The Industrial Raspberry Pi Forum

Our Monitoring solution provides about 10 different measurement data as ASCII files every few hours to a terminal-box close to the sensor.
This terminal-box has RS485, Ethernet ports - we currently use ETHERNET and add FO converters to communicate with a windowns PC in the control-room (few hundred meters away)
The remote PC in the control-room runs a proprietary app to view the data and control (change of alarm-levels, measurement frequency etc...)
This is working "almost" perfectly.
We wish to modify some of the Data (format-issue with ASCII files / CSV etc) and we wish to add other data from additional sensors.
We consider to "add" a few raspberry modules - for CPU, analog-digital IO for the new sensors - and to merge the existing data into the same set.
I'd need your help / advise - so that we can use the "same" data-transmission lines - one ETHERNET port, we may need ETHERNET gate/splitter, and may need to add other TCP/IP addresses ...
If this is a workable solution, I'd need support to do the application programming as well.
Communication is running currently via TCP/IP protocol. Modbus RTU available as well, but not jet tested. File-Viewer option maybe???

You can use a RevPi Connect or RevPi Core 3 Module together with AIO modules to implement a sensor application for analogue values. The RevPi works with a process image. So the analogue sensor data is cyclic updated in the RevPis process image that you may access i.e. by C, Python or Node Red or a soft SPS like LogiCad to implement the data exchange.
I think the new RevPi Connect is the perfect device for you. You have the ability to use two separate ethernet RJ45 interfaces and you have a RS485 interface as well.
So if you want to use ModbusRTU you are ready to go without extra hardware. ModbusRTU/TCP Master/Slave are well integrated and access the process image.
Have a look at our Video tutorials to see how easy you may access Modbus data.
Node Red is a free and user friendly tool which is already available on the device. It enables you to quickly create this kind of application that acts as a data gateway for sensor values.
As we do not know more about your "terminal-boxes" protocol we cannot give you advices how to integrate the RevPi Devices to your existing application.
But i.e. by using a ModbusTCP Master or using HTTP file transfer with a CSV file you can just plug into your existing Ethernet network to provide access to the collected sensor data.