How to use adressing in Modbus (rs-485)

Projects Networking, Protocols, and Devices
1

Hi,

My current situation:
I have 4 PT100 sensors, which are connected to z-4rtd2 which converts the signal to rs-485(modbus).
I also have a Humidity/temp sensors which is conncted to z-8ai which is converted to rs-485(modbus)

I am looking for a way to communicate my arduino UNO to rs-485 and to read all of these sensor values?

Basically what happends here I have an UNO and I have 5 sensors on RS-485. In total 2 RS-485 devices, one RS485 device that has 4 sensors, the second one has 1 sensor.

  1. How do I adress the sensors, they each have specific adressing (in the UNO) so I can read values from them?
  2. And most importantly how do I put it in the code, I have no idea where to start.. but in order to do something I need real live examples, I am quite a beginner at this...?

And no, the Modbus library Arduino official site offered wasn't really helpful for me.

Thanks in advance,
Linkers

2

hi
I am not an expert I'm just asking this out of curiosity. what module do you use to change ttl to 485?

I think this is very important to change protocol right. I'm wondering if you could make a RX or TX blink on the slave part?