Re: Interface on low-cost linear scales?

The vast majority of Linear Scales, output
a quadrature signal, either Analog or Digital.

Most Digital Output units will have 4 wires...
Gnd, +5V, A Output and B Output.
The outputs being standard logic TTL or CMOS
levels.

The Analog units can have 4 but usually 6 wires.
Gnd, +Vcc, A+ Output, A-Output, B+Output
and B-Output

Analog levels can very from microvolts to
several volts. These are usually sine waves.
Some are Open Collector Outputs, so if you
apply power and still don't read an output,
you may have to use pull-up resistors.

In either case your going to have to figure
which pins are Gnd and Vcc first.
This will probably require opening up one of
the units and figuring it out or drawing a
schematic.

Also there might be a clue as to the
manufacture on the circuit board.

Good Luck

Tom M.