SPB PLC Fuji Programming an Encoder


Thread Starter

Hiram Ziehl

Hello Guys,

I'm sales person with these company, I have a company who is using FUJI PLC's SPB series. They are buying PLCs with a relay output and the High speed counter are the inputs X0....X3

These guys ask me how they can program an encoder with these type of PLC for a new project. If I gave them prompt response they will buy some items from me.

Can you let me know what type of instructions use to program it?

Thanks for your support,

Robert Scott

Ordinary counters can be used to read encoders, but only if the encoders are going in only one direction. If you need to be able to track an encoder in both directions, then you need a true quadrature decoder. A quadrature decoder takes in the A and B channel phases (90 degrees out of phase) and produces up counts and down counts depending on the direction of rotation. These up and down counts can be counted on two separate counters which are then subtracted to give the actual position. Normally, the quadrature decoder and up/down counter are integrated into a single "quadrature counter", but sometimes they are implemented separately.

-Robert Scott
Real-Time Specialties
Embedded Systems Consulting