摘要 |
An open circuit detection apparatus is provided for detecting whether a connection is closed between a local node and a remote node having a known impedance. A ping source is connected to the local node. The ping source has an output for transmitting an address unique to the remote node and an input for sensing the impedance of the remote node. A test circuit is connected to the remote node. The test circuit has an address decoder for receiving the address from the output. The address decoder has a unique address and asserts a control signal upon the address matching the unique address of said address decoder. An impedance-varying device is responsive to the control signal and effects a change in the impedance of the remote node. The change in the impedance of the remote node is sensed by the input of the ping source.
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