6250 And AT6250 Third Encoder Port

The 6250 and AT6250 both have a third encoder port for following. This encoder port does not have to be used for following and it can be used as a read only encoder port. The PSET command does not work on this 3rd encoder port. Here is an option to get around this:

You can set the 3rd encoder port as a master even though it will not be used in following. This can be done with the FOLMAS31 command. As soon as the FOLMAS31 command is executed, the encoder pulses on the 3rd encoder port are monitored and stored in the PMAS command. Instead of reading the encoder with the PE command, you can read it with the PMAS command. Then you can adjust the PMAS counter with the command FMCNEW1. The new PMAS value with be set to the FMCP command. Here is a breif example: