REXYGEN Community Forum

pama

Member

Registered: 2016-08-22

Posts: 9

connecting multiple devices

Hi,

just checking now the examples, seem interesting and promising.
My question is how should I connect multiple devices on distance, i mean as a hobby project to connect some valve and sensor on garden, but all kind of point should be at 30-50 meters from each others.
I mean like on industrial enviroment we use simens cpu connected over profibus to et200 distributed io's.
Of course no safety issues, just hobby project.... Because I would trace some power cable underfloor, but for command part maybe would be some raspberry as master, and some other as slave, connected trough some wifi ....i do not see any other serial protocol wich could be used,
thanks and all the best,pama

jaroslav_sobota

Administrator

Registered: 2015-10-27

Posts: 535

Re: connecting multiple devices

Hi pama,
yes you can have one RPi as master and one or more RPi as slave(s). For data exchange you can use:
1) Modbus TCP, see https://github.com/rexcontrols/REXexamp … a_Exchange
2) UDP communication, see https://github.com/rexcontrols/REXexamp … r_Receiver
3) RDC function block (not available in demo version), see https://github.com/rexcontrols/REXexamp … DC_example

All options will work via Ethernet or wifi.

I recommend Modbus TCP because it takes care of data integrity, reconnection in case of temporary network failure, etc.

Hope this answers your question. If you need additional information, I'll be happy to help.

Jaroslav

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Monarco HAT for Raspberry Pi - Lightweight I/O for monitoring, archiving and control.
Raspberry Pi in industrial automation!

pama

Member

Registered: 2016-08-22

Posts: 9

Re: connecting multiple devices

Hi Jaroslav,

thanks kind. I will try to reserve some time to pass trough the bassic usage and i'll comeback, if there'll be some questions,

have a good day,pama