Hello.
I'm planning to use a 3v3 board and a rs485 interface as master of a modbus network.
Slaves are arduino 5v based. They will use MAX485.
What rs485 IC must I use in 3v3 master board?
Some RS485 ICs allow 32, 128, ... slaves. Can I mix different ICs in the same RS485 network? I've got different samples from maxim.
Thanks.
Maxim do '3' versions of the comms chips....
Max3232 is the 3.3v version of the Max232
Max3485 is the 3.3v version of the Max485 - Mixed-signal and digital signal processing ICs | Analog Devices
Can I mix different ICs in the same RS485 network?
Yes, the voltage level on the logic side doesn't matter and they all have to conform to RS485 on the line side.
RS485 can handle 32 Unit Loads (ULs) as long as you don't exceed that you will be right, so you cam mix 1/8th UL chips and 1/4 UL chips etc.
Rob
Thank you.
Very good answer.