YoYo,
"This way I can have multiple RS-485 slave devices off the PLC without having to have a RS-485 interface on the PC; and I should be able to read them all from HomeSeer through a single serial connection."
So you'll program the 1st PLC to scan the other (2..n via RS485 daisy chain) PLC's and store the information in the the 1st PLC? And then connect to the 1st PLC using RS232 and retrieve all the scanned data?
It might be simpler if use an RS232-RS285 converter at the PC and just daisy chain all the PLCs. Then scan the PLC multidrops as needed; this would avoid having to program (and maintain) the scanning program in the 1st PLC.
Mark
"This way I can have multiple RS-485 slave devices off the PLC without having to have a RS-485 interface on the PC; and I should be able to read them all from HomeSeer through a single serial connection."
So you'll program the 1st PLC to scan the other (2..n via RS485 daisy chain) PLC's and store the information in the the 1st PLC? And then connect to the 1st PLC using RS232 and retrieve all the scanned data?
It might be simpler if use an RS232-RS285 converter at the PC and just daisy chain all the PLCs. Then scan the PLC multidrops as needed; this would avoid having to program (and maintain) the scanning program in the 1st PLC.
Mark
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