Hello.  I have a Yaskawa Servo Drive and Motor that power the Z axis on my router.  The Z axis also has a brake that is built into the motor.  I am putting in a new CSMIO controller and am not sure if I should use Mach3 to control the z axis brake or if I should let the servo drive control it.  Currently, the brake is wired up on a relay that was controlled by the last cnc controller that it had in it.  I know for sure the Yaskawa drive can disable and enable the z axis brake when it needs too, but, it currently isn't wired to do so.  I have a couple questions:

1. Which is a better setup? To let the cnc controller control the brake, or let the servo drive control it? 
2. The z axis also has a pneumatic cylinder on it to help offset the spindle weight, and so I am not exactly sure if the brake is needed to keep it from falling while the cylinder has pressure, or if the brake is used only when the machine is powered off/no pressure.   Any ideas on how to determine what the brake is actually needed for?

Any help would be appreciated.  Thank you

It was common for a spindle brake to be used to enable faster tool changes to be made on the ATC equipped machines but changes to certain industrial regulations have now made cutting device brakes mandatory on some machines (typically, circular saw benches) - perhaps check the regulations in your country.

I would be inclined to let the drive control the braking.

Tweakie.

I got an DMM AC servotor 1.8Kw with brake on my Z-axis. I let the drive control the brake, and it works fine. If the drive loses power or goes in error
Mach3 or Mach4 wont notice at all.. If you dont have a alarm signal from drive to Mach. Its bether to make sure the brake are active unless drive are live. I actually got an Reset button on my machine that trigger a relay powering all my drives. If I get an ServoDrive error I can just kill them all for a sec and move on. Mach doesnt care at all.