本实施规程规定了适用于评估处理SMPTE 292M中定义的高清串行数字视频信号的设备低频响应的数字测试信号。虽然一系列信号将产生所需的低频效果，但定义了两个特定的信号，分别用于测试电缆均衡和锁相环（PLL）锁定。在过去，这两种信号被通俗地称为“病理信号”

This practice specifies digital test signals suitable for evaluating the low-frequency response of equipment handling high-definition serial digital video signals as defined in SMPTE 292M. Although a range of signals will produce the desired low-frequency effects, two specific signals are defined to test cable equalization and phase locked loop (PLL) lock-in, respectively. In the past, these two signals have been colloquially called "pathological signals."