Some users have asked about single ended encoders. Although i recommend to try to run differential if possible, your machine may already have Single ended encoders.

After doing some testing ,i've found the un-used encoder input to the viper should have a 2K pull down resistor.

You can put 2 resistors in the 9 pin plug that attaches to the viper.
--------------------------
On the Encoder plug connect like this

pin 5 A channel
pin 4 2K res to pin 8(gnd)
pin 3 B channel
pin 2 2K res to pin 7(gnd)

pin 1 +5V for encoder
pin 9 (power gnd) for encoder


note: Pins 9,8,7 are gnd
(pin 6 is not ground and should not be used)
---------------------------

The reason for the 2K res is in the viper there are 2K pullup resistors on each encoder pin. Adding the 2K pull down puts the differential input pin at center voltage and disables it.

Single ended encoders with a very course count of 200 counts or lower, should be replaced with a 500 count or greater differential encoder for smoother control.

Larry K