Talon FX Neutral Brake Current Limit

Technical Programming
1

Hi,

We’ve been running into an issue when putting Talon FX into brake or coast and then back driving them, as they get a “Neutral Brake Curr[ent?] Limit” sticky fault. The motors in coast aren’t affected, but the ones in brake seem to fall back to coast. I haven’t found any documentation on what Neutral Brake Current Limit is, but I’ve tried to change the Talon’s Stator & Supply current limit and threshold current limit to 231 through Phoenix Tuner, and still get the sticky fault. I haven’t been able to find any documentation on what the fault means, how it is generated, and how to prevent it. We haven’t even been back driving the motor at full power, when graphing the stator current the max is about 20-30 amps.

Thanks for your help

2

If I had to guess, the fault condition is excessive current through the stator while in brake mode, caused by rapidly back driving the motor while in brake mode. I’d prevent it by not back driving the motor so quickly.

3

Update: We are also getting the fault on the drive train, which is all in coast mode

4

I’m having a similar issue right now. The motor will enter neutral mode every 0.5 seconds (the time fluctuates). No idea where it comes from. The stator and supply current are only less than 10Amps.