We have 3 devices (2 GE Horner slaves and CAC 5600 RTU) talking Modbus ASCII over 4 wire RS485 network. Client wants to add a radio (MDS1000) for communication with the SCADA system. How to key the radio? As I understand, CTS is required. Our RS485 has Tx- Tx+ Rx- and Rx+. Is there any RS485/RS232 converter suitable for that task?