The TDH2 is a 9600baud half-duplex multi channel OEM radio modem with a power output of 25mW. It is a 100% pin-compatible drop-in replacement for the Radiometrix TDL2A and can be used to replace the TDL2A in applications where greater radiated power is desired. TDH2 acts as a transparent serial cable to attached host. TDH2 is an intermediate level OEM radio modem which is in between a raw FM radio module like BiM2 and a sophisticated OEM radio modem like SPM2. It takes care of preamble, synchronisation, bit balancing and error checking along with automatic noise squelching.