I need to set up a network of radio modems, slave/masters, in order to gather industrial data from remote oil well sites. Each well site has 3 separate devices that can independently interface to a Modbus RTU master (in this case a Honeywell C200 PLC) using Modbus protocol. I intend to daisy chain the 3 devices using RS485 data transmission and then convert to RS232 for radio modem transmission. The problem I face is I don't know anything about how to map the individual device parameters and then decipher them in the Honeywell PLC for display on the control station. Where can I find this information directly (without endlessly searching Web sites)? Any help is much appreciated.