VW3A3424 is HTL encoder card used for Altivar Process ATV900
It can work with A, /A, B, /B signals or with A and B only or with A only.
The component signals /A and /B must be connected to the encoder card either 0V or to V+. It depends on the type of encoder signals.
If the encoder is the push-pull type that provides A and B signals, then missing component signals /A and /B must be connected to 0V
Likewise in an open collector encoder if the output signals are of PNP type, missing /A and /B must be connected to 0V.
For NPN type the missing /A and /B must be connected to V+ of the encoder card.
See the highlight on an extracted page from the encoder card instruction sheet.
It can work with A, /A, B, /B signals or with A and B only or with A only.
The component signals /A and /B must be connected to the encoder card either 0V or to V+. It depends on the type of encoder signals.
If the encoder is the push-pull type that provides A and B signals, then missing component signals /A and /B must be connected to 0V
Likewise in an open collector encoder if the output signals are of PNP type, missing /A and /B must be connected to 0V.
For NPN type the missing /A and /B must be connected to V+ of the encoder card.
See the highlight on an extracted page from the encoder card instruction sheet.