How does your wiring compare to the description:
Wiring Output:
A phase, B phase, Vcc positive supply, V0, the shield wire.
Connection:
Green = A phase, white = B phase, red = power +, black = V0
Note: AB two -phase outputs must not be connected directly to VCC, otherwise, they will burn the output transistor.
Output
AB two -phase quadrature output rectangular pulse, the circuit output is NPN open collector output type ,the output of this type can and with additonal added pull-up resistor(not included) is directly connected MCU or PLC, such as 51 single or Mitsubishi PLC (PLC input mode should be connected to 0V switch function ).
Note:
If the encoder is not connected to the device can not be directly connected to oscilloscope ( open collector output without pull-up resistor when there is no voltage output) If you want the oscilloscope in AB two-phase output, work with two pull-up resistors(not included).