PC485: RS232 to RS485 adaptor
The PC485 is designed to convert a computer (PC) serial RS232 COM port to RS485 for use with SPLat controllers. It's primary application is systems that use ModBus protocol to connect one or more SPLat controllers to a PC.
The PC485 will work only with half duplex communication protocols like ModBus RTU. It uses start bit detection to switch from receive mode to transmit mode. This uses a fixed interval timer that will only work correctly at 9600 BPS.