HEIDENHAIN TNC 306 Technical Manual - Manual (Page 160)

4-60
TNC 406/TNC 306 4 Gap control 3/97
Machine parameter MP2050 defines a distance to the last eroded position for traverse at the feed
rate from MP1090 or MP2060, or from the NC program. From this point on the characteristic curve
is active again.
MP1090 Feed rate for reapproach
Entry value: 0 to 30 000 [mm/min]
MP2060 Feed rate for retraction during erosion (M2620)
Entry value: 1 to 500 [mm/min]
MP2050 Distance to eroded position during reapproach (M2617)
Entry value: 1 to 500 [µm]
Set Reset
M2617 Electrode retracts as long as the marker is set PLC PLC
M2620 Feed rate from MP2060 becomes active
(for special applications, e.g. feed rate via key)) PLC PLC
M2780 Electrode is retracting / reapproaching NC NC
M2781 Maximum retraction point has been reached NC NC
M2784 Electrode is reapproaching NC NC
4.4 Arc recognition
If a voltage between 0 V and 2.5 V (negative feed rate) is measured at the analog input for the
duration entered in machine parameter MP2120, the control positions the electrode to the beginning
of the last executed erosion block and switches erosion off with M37. Then the error message
"ERODING ERROR" is output. Marker M2788 is set at the same time.
If the control should automatically continue the program run, the start marker M2642 must be set by
the PLC. Marker M2788 is then reset by the NC, the error message is cleared and the reapproach
point is sought. If it is found, the control resumes program execution at the reapproach point. If the
reapproach point is not found, the NC program is at the program beginning, since the search is
aborted at the END PGM block of the main program.
MP2120 Time for arc recognition
Entry value: 1 to 99.9 [s]
Set Reset
M2642 Start marker after faulty erosion process PLC PLC
M2788 Error message is displayed NC NC