When I feedhold on my waterjet gantry, the Gecko's (g320's) will fault out. Usually one or sometimes both. Are the ramp settings on the motors set too aggressively, or is it something else? Thanks in advance

Cant see how feedhold can do that as it is a controlled stop and if a normal rapid doesnt trip the drives when it stops moving then no way a feedhold should, I take it you can do a rapid move without issues?

Hood

rapid is no problem only feedhold

Does it fault right away? 
Does Mach go into reset or is it just the drives that trip?
Any message in the ticker window in Mach?
Are you using the standard screenset?

Hood

Actually, after looking at it closer, it faults on rapid moves if I hit "stop". I am using the Machblue screenset. Just the drive or drives trip. Mach does not fault and has no message.

Stop will almost always fault if you use it when in motion as it stops pulses instantly and your momentum is highly likely to carry your axis beyond the following error limit of your drives and thus fault them. Feedhold should not do that though as it is a controled stop where Mach will decelerate at the rate set in motor tuning.
If frrghold is causing a problem then there is something wrong, try the standard screenset as it could be a hotkey or even an OEM code miss set in the screenset you are using.
Hood

I will try that. Thanks for your help

The Gecko site has a diagram to wire the err terminal into Mach so it sees the drive fault and goes into e-stop