The ICM4 serial converter module provides the capability of interfacing equipment with RS485 serial communications to equipment with RS232 communications. Data format of the RS232 and RS485 equipment must be the same. For full duplex (RS422), the DIP switch on the side of the module must be in the RS422 position. For half duplex (RS485), the DIP switch must be in the RS485 position. In half duplex mode, the RS485 driver is enabled using the leading edge of the first character transmitted (RXD input). After the last character transmits, the converter waits one character time (at 9600 baud) to disable the RS485 driver. There are 3 LED’s that can be viewed from the front of the converter module. A green power LED indicates power is on, a red RS232 TXD LED flashes when the module is transmitting, and a green RS232 RXD LED flashes when the module is receiving. An external DC power source (9 to 32 VDC) is required to power the ICM4. The external power source and serial communications connections are made via a 12 position removable terminal block located on the front of the module. The unit is equipped with a universal mounting foot for attachment to standard DIN style mounting rails, including top hat profile rail according to EN50022 - 35 x 7.5 and 35 x 15, and G profile rail according to EN50035 - G32. Power: 9 to 32 VDC 75 mA maximum. Above 26 VDC, derate max. operating temperature to 40 degree C. Power supply must be Class 2 or SELV rated. CE approvals.