Galil DMC-3425 user manual Limit Switch Routine, Limit Switch Example

Limit Switch Routine

The DMC-3425 provides forward and reverse limit switches that inhibit motion in the respective direction. There is also a special label for automatic execution of a limit switch subroutine. The #LIMSWI label specifies the start of the limit switch subroutine. This label causes the statements following to be automatically executed if any limit switch is activated. The RE command ends the subroutine and resumes the main program where it left off.

The state of the forward and reverse limit switches may also be interrogated or used in a conditional statement. The _LR condition specifies the reverse limit and _LF specifies the forward limit. A or B following _LR or _LF specifies the axis. The CN command can be used to configure the polarity of the limit switches.

Limit Switch Example:

Instruction	Interpretation
#A;JP #A;EN	Dummy Program
#LIMSWI	Limit Switch Utility
V1=_LFA	Check state of forward limit
V2=_LRA	Check state of reverse limit
JP#LF,V1=0	Jump to #LF if forward limit = low
JP#LR,V2=0	Jump to #LR if reverse limit = low
JP#END	Jump to end
#LF	#LF
MG "FORWARD LIMIT"	Send message
STA;AMA	Stop motion
PR-1000;BGA;AMA	Move in reverse
JP#END	End
#LR	#LR
MG "REVERSE LIMIT"	Send message
STA;AMA	Stop motion
PR1000;BGA;AMA	Move forward
#END	End
RE	Return to main program

NOTE: An applications program must be executing for #LIMSWI to function.

154 • Chapter 8 Hardware & Software Protection DMC-3425