Re: simple (low cost) encoder readout software ?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

>
> Hi all,
>
> In my recent scaverenging of old plotters and printers, I have come
> across a bunch of encoders.
>
> I was wondering if there are any low cost or free software packages
> that I can use to read out what these things are rated for ?
>
> Some of these are old and not part numbers.
>
> Dave

Dave, your first challenge will be to see if they are dual output
encoders that can be used in quadrature. There are a lot of encoders
where direction is not a issue and they just give single pulses to be
used for velocity or speed feedback.

Start by counting wires. You need at least 4. (+, - , A, B) Less
than that and you may not have a digital encoder. Your next
challenge is to determine + and - power leads. A lot of encoders
will use Red and Blk as + and - respectively. YOu might have to open
the encoder and try to determine from electrolytics or active
components waht are power and ground leads. If its a sealed unit and
the color codes are weird and there is no valid part number then you
may be SOL. If it were me I would build a simple two LED tester that
had buffered LED's that would turn on when the input to the buffer is
high. Just some simple transistors would work. If there is some
intrest for this I will draw and post a schematic. This won't get you
the line count but it would allow you to determine the lead
configuration. If you get far enough to make the leds flash as you
turn the shaft then a counter hooked up to one of the signals and
going one revolution of the shaft will give you the basic line
count. Have multiple ground inputs so you can handle differential
encoders. They will have two leads for each channel. Then there
might be an index pulse with separate leads.

What you are describing is a hardware issue and there will not be a
magic piece of software that will just let you randomly plug in the
leads and then figure out which is which. I guess the closest thing
would be a logic analyser where you can see 8 or 16 channels of
digital data at the same time. You would still have to figure out
the power and ground issue. There might be encoders with open
collector outputs, 12V or higher operational voltage, and other
strange stuff.....mumble, mumble.......heck I DON'T KNOW!!!