FEC AFC1500 - Manual (Page 114)

Chapter 6: Fastening Instructions
Page 6-28
6.6.8 Rundown Revolution Limits
Rundown Revolution high and low limits can be set to identify fasteners that may be too long or too
short for normal operations or for a redundant check for bolts that reach torque but are not seated.
This is especially the case where different length fasteners are used and placed by hand. The num-
ber of rundown revolutions until fastening end is monitored and judged. Rundown Revolutions is
measured from the start of revolution to fastening end. This can be used in conjunction with the Low
1st time limit. (6.2.5)
Note: Since fastener engagement is not always 100% guaranteed (& this is counted as revolution),
bolt length differences must be enough for detection without setting limits too tight or problematic re-
jects may occur. Also, if bolts are hand started (with a variable starting point) this function is not rec-
ommended unless the bolts are pre-started to the same point every cycle.
6.6.9 Torque Inhibit
The Torque Inhibit function is used to ignore high torque spikes during initial starting of the motor or
fastening process. Under normal fastening operations peak torque will stop the fastening process (if
Standard Torque is reached). This may not be desirable for applications with high starting torque and
lower fastening torque. Applications such as self tapping screws, nylok nuts, crushed fasteners, and
application with high starting inertia may require this function.
Torque Inhibit is set by the number of revolutions that is required to be “ignored” during the process.
The Torque Inhibit Limit is a torque limit used as protection in case the amount of torque monitored
during the Torque Inhibit Revolution is too high. If this torque limit is hit during the Torque Inhibit
process, then the spindle will stop and an Abnormal is output.
Fig. 6-6-9 Torque Inhibit Function
WARNING: The Torque Inhibit Rev setting should be set as low as possible for the intended application
to avoid ignoring torque readings as the fastener approaches the seating point. If the fastener seats and
the system is still in Torque Inhibit mode, possible fastener/part and/or system damage may occur.
6.6.10 Fastening End by Self Check Off Signal
The Fastening End by Self Check Off Signal function is used when a specific Torque or Angle Target
must be reached prior to a final positioning operation. This function allows the system to fasten to its’
Target value and than continue to fasten until either the HIGH limit is reached or the “Fastening End
by Self Check Off Signal” input (section 4.7.1) is activated. This ensured that both the Target and the
proper position are attained. (Function is enabled by AFC software)
Speed
Initial
Initial Time
Torque
Slow Down
Freerun
Torque Inhibit
Revolutions
Freerun
Revolutions
1 st Time Final