Rockwell Automation 999 IMC S Class Compact Motion Controller (Cat. No. 4100-999-122) - Manual (Page 108)

5-28 Understanding IMC-S/23x Setups
Publication 999-122 - January 1997
The IMC-S/23x can be configured to perform both overtravel limit
switch checking and software travel limit checking to prevent a
physical axis from traveling outside pre-defined limits and possibly
causing damage. If overtravel limit switches are used, they may be
specified as having either
NORMALLY OPEN or NORMALLY CLOSED
contacts. Toggle to the contact type which matches your switches and
press ENTER.
Overtravel Limit Switches
If overtravel limit switches are used, they are active whenever the
IMC-S/23x is operating. Activating either the positive or negative
overtravel limit switch at any time causes a hardware overtravel fault
on the axis (
HRD LIM displayed in the status field of the Standard
Operator Interface) and causes the fault action specified by the hard
overtravel action parameter in the application setup menu to occur.
Software Travel Limits
The IMC-S/23x also provides programmable software travel limits.
Exceeding these position limits results in a software overtravel fault
(
SFT LIM displayed in the status field of the Standard Operator
Interface).
If software travel limits are used, enter appropriate values for the
maximum travel in both the positive and negative directions. Both of
these values are entered in the position units of the axis. If you enter a
maximum positive travel value less than the maximum negative travel,
the IMC-S/23x displays
!
ATTENTION: Even though the IMC-S/23x provides
overtravel protection while it is operating, for utmost
safety, the overtravel limit switches and/or the CPU
watchdog contacts should also be hardwired into the
drive amplifiers so that drive power is interrupted if a
fault occurs.
!
ATTENTION: Hardware overtravel switches should
be wired normally closed to provide failsafe operation.
TIP: Use both overtravel limit switches and software travel limits for
utmost protection.
Max Neg Travel (Position Units) =
*** Neg Limit Must Be < Pos Limit!