S-Override - HEIDENHAIN TNC 415 Technical Manual

4.1.3 S-Override

The spindle speed can be altered within certain limits by the S-override potentiometer . These limits
are fixed by machine parameter MP3310. However, the upper spindle speed-limit from MP3515
cannot be exceeded by S-override.
The %-factor which is adjusted by S-override is kept in Word W492 and W764. However, W764 be
changed by the PLC. As soon as a different value is entered here it will be adopted by the NC. In this
way the %-factor can be influenced by the PLC .
If W764 is not changed by the PLC, the normal override-function remains active.
MP7620 bit 3 determines whether the override is effective in 1% steps or according to a non-linear
characteristic curve. In the non-linear characteristic, the lower range changes in 0.01% steps, and in
the range over 2.5% the step is 0.75%. The range of override values in W492 and W764 lies
between 1 and 150 in 1% steps for the linear characteristic, and between 0 and 15 000 for the non-
linear characteristic.
MP3310.0 Limit with S-override (maximum)
Entry: 0 to 150 [%]
MP3310.1 Limit with S-override (minimum)
Entry: 0 to 150 [%]
Word Function
W492 %-factor - spindle-override
(NC → PLC)
W764 %-factor - spindle override
(PLC → NC)
MP7620 Feed-rate and spindle override
Entry: %xx0x
Bit 3 Override in 1% steps or non-linear
0 = 1% steps
1 = non-linear
01.98 TNC 407/TNC 415/TNC 425
Set
NC
NC; PLC NC; PLC
4 Main Spindle
Reset
NC
4-99