Siemens SINUMERIK 808D ADVANCED Programming And Operating Manual page 134

The cycle creates the following sequence of motions:
● Approach of the reference plane brought forward by the safety clearance by using G0
● Oriented spindle stop (value in the parameter POSS) and switching the spindle to axis mode
● Tapping to final drilling depth and speed SST
● Dwell time at thread depth (parameter DTB)
● Retraction to the reference plane brought forward by the safety clearance, speed SST1 and direction reversal
● Retraction to the retraction plane with G0; spindle mode is reinitiated by reprogramming the spindle speed active before
the cycle was called and the direction of rotation programmed under SDAC
Explanation of the parameters
For more information about the parameters RTP, RFP, SDIS, DP, DPR, see Section "Drilling, centering - CYCLE81
(Page 125)".
See the following parameters for CYCLE84:
DTB (dwell time)
The dwell time must be programmed in seconds. When tapping blind holes, it is recommended that you omit the dwell time.
SDAC (direction of rotation after end of cycle)
Under SDAC, the direction of rotation after end of cycle is programmed.
For tapping, the direction is changed automatically by the cycle.
MPIT and PIT (thread lead as a thread size and as a value)
The value for the thread lead can be defined either as the thread size (for metric threads between M3 and M48 only) or as a
value (distance from one thread turn to the next as a numerical value). Any parameters not required are omitted in the call or
assigned the value zero.
RH or LH threads are defined by the sign of the lead parameters:
● Positive value → right (same as M3)
● Negative value → left (same as M4)
If the two lead parameters have conflicting values, alarm 61001 "Thread lead wrong" is generated by the cycle and cycle
execution is aborted.
POSS (spindle position)
Before tapping, the spindle is stopped with orientation in the cycle by using the command SPOS and switched to position
control.
The spindle position for this spindle stop is programmed under POSS.
Programming and Operating Manual (Turning)
134
6FC5398-5DP10-0BA2, 06/2015