I'm trying to measure the on-off control signal from a NPN open collector output using a data recorder, but I'm not getting a correct waveform.
我想用记录仪测量NPN集电极开路输出的ON/OFF信号,但是无法观测到正确的波形。
Could you describe the problem in more detail.
能具体描述一下问题吗?
There is no on-off square wave and the wave keeps fluctuating at zero volt. Could there be something wrong with the wiring?
看不见ON/OFF的矩形波,总在0 V附近波动。 是不是配线有问题?
That could be the problem. If the NPN open collector output is not connected to any other equipments, you need a load resistor and an external power supply.