When is the compressor supposed to run in competition?

[tkbletsc]

We just got our compressor working with cRIO control, but it seems to power on only in teleop and autonomous, not in disabled.

It seems like at the start of autonomous, we'd want pressure already available without waiting for the compressor to charge up our tank.

We're a rookie team, so we don't know the mechanics of competition. Is there time for us to charge the compressor before the match? Once the robot radio is configured for field use, would we even be able to control it to enable the compressor ourselves?

If not, what do people do about pressure...do teams just wait for it to build during the match before being able to start shooting?