INCREMENTAL ENCODER

[fabuena]

Hello, 
I want to connect a CALT GHW38 incremental encoder with a built-in measuring wheel to my KC 868-A8 in the simplest way possible. 
Should I get an NPN, PNP, or 5V line driver encoder? 
Dispositivo de Medición de Longitud CALT GHW38, Codificador Rotatorio con Salida de Pulso, con Rueda Antideslizante de 200 mm/300 mm de Circunferencia - AliExpress

Which inputs do I connect signals A and B to?

Thanks

[admin]

KC868-A8 digital input: 0V=true 12V=false.

[fabuena]

KC868-A8 digital input: 0V=true  12V=false.

Thank you very much!
So I must buy a NPN encoder, right?

[admin]

yes, chose NPN type.