We are looking into installing multiple pressure/flow meters of a brand which supports Modbus RTU/TCP/TCP+POE.
The first 6 machines require a total of 20 devices and could reach up to 60 in the factory.
Whats the best approach/solution where we can connect multiple devices to a box/gateway which only uses 1 single UTP connection instead of patching each individual devices which means we have to add a lot of new cables.
I found the following device and I wonder if this would work?
https://www.phoenixcontact.com/en-au/products/switch-fl-switch-1000-8poe-gt-1102079
Your flow meters have Modbus TCP, don’t waste time on Modbus RTU. Also the switch above is PoE, so it will power the meters from the switch.
Given an Ethernet connection, the meter config and status is likely on a web browser, so why remove that ability?
That's a solid approach.
By default it's RTU and for €300 per piece it's TCP, that's €3000 whereby I would need 3 switch for another €1500.
I was looking for an good alternative option to compare the estimated cost.
You can daisy chain Modbus RTU with RS-485, but it is terribly slow, even if you bump the baud rate way up. You can save money, but be prepared for disappointment. The Moxa Modbus TCP gateway devices are a good choice if you go that route.
I challenge you to price up the time and materials of running daisy chains of modbus cable and the price and time needed for terminating to DE9 connectors on a modbus converter and also the power runs back to your board for every single device, coupled with the extra comissioning time because you don't have a configuration link when it is fully installed. Compare that to a simple star made with a PoE switch that solves data, power, config and halves the cable runs. That is where the cost comparison is on these projects.