How to check signals of Rotary Encoder with a digital multimeter as we donot have oscilloscope at working site

Answer 1

..and if it's a quadrature-output (probably more likely) you would get alternate high-lows on each of the 2 outputs as you krank the knob. This will probably be about the best you can do (tho it should be enough) without a scope - kinda hard to check for the 90/270-degree phase relationship with just a meter unless the encoder has unusually-large steps. If it is this type, and you have a schematic, can you go to the logic that the encoder feeds? The output of the logic should have a "Direction" and a "Counts" output. "Direction" (or whatever your circuit calls it) will be high in one direction of rotation and low in the other, with pulses coming out of the Count line in both directions.

Answer 2

Assuming that the encoder is producing a gray scale digital signal this would be very difficult, as you would need to read all bits (probably about 8 or so) and make a table while rotating the encoder in very small steps, also very difficult. At a basic level you can just make sure that each of the bits toggles and is not stuck to one or zero. Or shorted to its neighbor.