Encoder Settings

Hi guys,

I've just joined PLCs.net yesterday and I am also new to PLC's. I am quite good in designing and reading circuit diagrams for relay controls(Hard Wiring) but now trying to get into PLC's also as we have lots of PLC controlled machine in our plant. Currently I would like to know that is there a way to test an encoder and set it to zero without actually going online to the PLC.

Cheers........

Viks.

Really this depends on the type of encoder and method of connection. Incremental encoders dont have a 'zero' the zero is determined by a homing process. This often occurs when the machine is started. Once started and homed you need to access the PLC to see the current postion.

The second type of encoders are absolute encoders. These output a value rather than a pulse train. If they are connected to digital inputs you can determine the current vale from the I/O lights, but remember that most absolute encoders use gray code rather than normal binary. Alternatively some absolute encoders use an interface called SSI, you have to have PLC access in order to determine current value.

This is a simple version, there are quite a lot of possibilities with encoders