MicroLink HART protocol modem with a USB interface, rugged enclosure, 6 feet cable, and HART mini-clips. Includes virtual serial port drivers. This manual describes the setup and operation of Viatran's Model 970 SMART A Bell-202 modem (only needed if using a PC based communicator program). Your HART Communicator uses the Bell 202 frequency shift key. (FSK) technique of high-frequency digital signals superimposed on a. The HART protocol uses the Bell 202 standard frequency shift keying (FSK) signal to communicate at 1200 baud. The module supports HART commands including interface with HART electronic transmitters : it is designed to enable the plant engineer to configure, configuration, a Bell 202 Modem, a RS 232 serial. Emerson Micro Motion 1500 Manual Online: configure digital communications, Configure Hart/Bell 202 Communications. The Digital Communications Parameters HART Device Interface Instruction Manual 2.2 Configuring a Single HDI . The FSK modem operates at Bell 202 standards with a 460.8 KHz clock. Configuring the AD5420 for HART Communication Compliance by Maurice Egan Logic 0, based on the BELL 202 communications standard. IMPLEMENTATION.Single-chip, half-duplex 1200 bits per second FSK modem. ▫ Bell 202 shift frequencies of 1200 Hz and 2200 Hz. ▫ 3.3V-5.0V power supply.