The Simex SRS-2/4-Z45 Converter Module, primarily employed to link MASTER devices with a RS-232 port to RS-485 bus, generally supports devices which manage Tx switching through RTS signal and devices that do not control Tx switching using the RTS signal (Tx switching is considered as fully-automatic in this case). An example would be an appropriately programmed computer that is capable of function as the system MASTER device.