What "Number of Axes per 62.5 µs PID Rate" means?

[Petr Spiller]

Hello,
i'm trying to build simple motion control system. I would like to control two servo motors, running independently and simultaneously. Currently i'm  thinking about NI 7342 controller connected to NI MID-7652 servo drive and two Maxon's servo motors. What i'm not sure of is meaning of "Number of Axes per 62.5 µs PID Rate". Is 7342 controller sufficient for such an application or do i need to go for 7352 model?

Regards,
  Petr

[Jochen]

Petr,

both, the 7342 and the 7352 can control two servo motors independently. The fastest PID rate you can reach with the 7342 is 62.5 µs per axis. That means that the PID loop can run with 125 µs when both axes are enabled. The 7352 has a faster DSP and can run the PID loop for both axes with 62.5 µs.

For most standard motion applications this is not an issue as they require even slower PID rates (e. g.250 µs) so if you don't need any of the advanced features of the 7352 (e. g. periodic breakpoint generation, onboard commutation for brushless motors,...) the 7342 should meet your needs.

Best regards,

Jochen Klier
National Instruments Germany