There are a few different ways to disable the hardware limits on the Model 4000. The most common method is to access the 4000 through the front panel.
Hit F1 to enter the 4000s access code.
Enter you password and hit enter.
Hit F3 for immediate mode.
Hit F5 for ENABLE.
Hit F6 for ETC
Hit F3 for HLIMIT
Hit F3 to disable the limits on the desired axis.
The 4000 line for immediate execution should look like
1ENABLE HLIMIT NO NO NO NO
The Hard Limits on the Model 4000 will now be disabled.
NOTE:The Fault lights on the front panel of the 4000 should be off.