The ELM627 is a complete circuit for detecting break signals on RS232 lines, in an 8 pin package. This is useful for remotely resetting circuits through a serial link. For convenience, this circuit also generates an output pulse on power-up. The timing threshold for break signal detection is user selectable, allowing the circuit to respond to transmitted null characters, @, at various baud rates. This provides a convenient means for the remote triggering of this circuit by simply shifting to a lower baud rate and sending a null byte. Two complementary high current outputs are provided by the ELM627, so that further buffering is not usually required. The output signal can be selected to be either a continuous one (following the TxD input line) or else a 100ms pulse output. No external components are required for circuit operation other than possibly a current limiting resistor, as all timing references are generated internally.