With the PWM-150A (VHF version) and the PWM-450A (UHF version), it is possible to perform protocol-transparent point-to-point and point-to-multipoint transmissions in analog networks. The devices are designed to communicate with nearly all standardized (and most non-standardized) M2M protocols and can be used as a central modem (control station) or as a remote station.

The PWMs feature an RS-232 interface (optional RS-485/422), which transmits at 9600 BPS with a CTS control line and requires a 12 V DC power supply.

The PWMs can receive serial data of up to 1000 bytes from a PC or PLC. This data is stored in a transmission buffer in the device until no further data is received. If there is a reception interruption of more than 10 ms, the CTS control line is activated to prevent further data transmission from a remote station. The device then adds a header and address line, synchronization data, and a 24-bit LRC/CRC checksum to the data set before transmitting it. All radio modems within the reception range with the same "Radio Air Address" will decode the data and, if the checksum is correct, output the data via the serial interface.