The ICM-3151 and ICM-3152 both provide electrical conversions from RS-232 signals at the Data Communication Equipment (DCE) to RS-422 signals at the Data Terminal Equipment (DTE) and vice versa.

For compatibility with MIL-STD-188C, the transmit and receive data (TD and RD) can be inverted through both units by a toggle switch. The units are transparent to all handshaking protocols and can accept data, clock, and control signals up to a maximum rate of 19.2 kbps for the ICM-3151 and 256 kbps for the ICM- 3152. FiberPlex recommends “R” units for high security applications because the units have added shielding and filtering to suppress their RFI.