Patent ID: 11539386

Abstract:
In the field of communications assemblies, particularly those arising in connection with high voltage direct current (HVDC) power converters, there is provided a communications assembly (10) that comprises a first module (12) which is arranged in operative communication with a second module (14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H) via a communication conduit (16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H). At least one of the first module (12) and the second module (14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H) have a receiver (24) that includes a squelch filter (26) which is configured to operate in a first normal mode and a second test mode. The squelch filter (26) normally operates in the first normal mode to suppress a signal output (28) from the receiver (24) when the strength of an input signal (30) received by the receiver (24), via the communication conduit (16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H), falls below a normal threshold. The squelch filter (26) selectively operates in the second test mode to suppress the signal output (28) from the receiver (24) when the strength of the input signal (30) received by the receiver (24), via the communication conduit (16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H), falls below a test threshold higher than the normal threshold. When the squelch filter (26) is operating in the second test mode, a signal output (28) from the receiver (24) indicates a signal margin in the communication conduit (16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H) that is at least equal to the difference between the test threshold and the normal threshold.