Watchdog Fault followed by Z+ Hardware Limit Check Fault

On one of my programs there is a point that is very close to the table maybe about 60-70 mm off the table. Every time I go to take this point I get a watchdog fault and it tells me z+ Hardware Limit Check Fault. Does this mean I hit my limit switch and this is as low as I can go? If so why is there a watchdog fault? Usually if I go too high in the Z or too far over in the X I get the Hardware Limit Check Fault but it will let me move away from this and continue with my work. I believe this is a machine issue and that I can actually go lower but something is not right.
Any insight on this topic would be wonderful, I am still learning on CMM operating and programming so try to be as descriptive as possible. Thank you!