HEIDENHAIN TNC 335 Technical Manual - Manual (Page 181)

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TNC 360 4 Spindle 8/95
4.1.3 Spindle override
The spindle speed can be altered within certain limits by the spindle override potentiometer. These
limits are fixed by machine parameter MP3310. However, the upper spindle speed limit from
MP3240 cannot be exceeded by spindle override.
The % factor which is adjusted by spindle override is kept in Word W492 and W764. However,
W764 can 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 nonlinear
characteristic curve. In the nonlinear curve, 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
curve, and between 0 and 15 000 for the nonlinear curve.
MP3310.0 Limit with spindle override (maximum)
Input value: 0 to 150 [%]
MP3310.1 Limit with spindle override (minimum)
Input value: 0 to 150 [%]
Word Function Set Reset
W492 % factor – spindle override NC NC
(NC
→
PLC)
W764 % factor – spindle override NC; PLC NC; PLC
(PLC
→
NC)
MP7620 Bit 3 Spindle override in 1% steps or according to a non linear characteristic
curve
+0 = 1% steps
+8 = nonlinear curve