We have a 4 tetrix motor drive on our bot. 2 motors have encoders, and 2 do not. I would like to "synch" the power of the motors without the encoders to the power commands resulting from the PID operating on the motors that have the encoders.

I know that synching two NXT motors is possible because of velocity matching using the encoders built in. I was trying to just match power for both motors on one side of the bot to the power commanded by the PID, in order to eliminate the requirement for 2 additional (expensive) tetrix encoders. I understand that matching the power does not match velocity, but it is closer than staying at the original fixed power.

Is the power commanded by the PID for the tetrix motors available by some means within a near real-time loop?

Thanks!

No.

The PID algorithm is managed within the microprocessor on the HiTechnic motor controller. The internal PID power settings are not visible outside of it -- i.e. ROBOTC firmware does not know about it.

Thanks for the information!