摘要 |
A communication device comprises a port via which the communication device is operable to communicate over a communication channel; command hardware operable to output a controlled signal over the communication channel; monitor hardware operable to monitor the controlled signal and output a controlling signal to block propagation of the controlled signal if a fault is identified in the controlled signal; and signal blocking circuitry coupled to a transmission path of the controlled signal and to a transmission path of the controlling signal; wherein, when the controlled signal is to be blocked, the signal blocking circuitry applies the controlling signal to the controlled signal such that a receiver at one end of the transmission path of the controlled signal identifies the controlled signal as a faulty signal; and wherein, when the controlled signal is not being blocked, the controlled signal is unimpeded by the signal blocking circuitry. |