Computer Drive Installation Instructions

12.93 6 NC Machine Data (NC MD), NC Setting Data (NC SD)

6.6.4 Axis-specific MD bits 1 (axial bits 1)

Bit 3 The actual value (actual position display) is converted into division positions. A

division position < 1 is not possible (applies to both rotary and linear axes). The

actual value display in the Service data is not converted into division positions.

If bit 3 is not set for a division axis, the position is assigned (over command

channel) in division positions but the actual value is displayed in mm or inches. Also

see Section entitled ”Functional Descriptions”.

Active: At once

Bit 2 The signs of the measuring-system pulses can be inverted by changing the state of

this bit (this is necessary when the axis traverses uncontrollably due to an incorrect

position control direction). This bit has no effect, if the spindle and the C axis have

the same actual value. In this case the spindle bit is active instead.

Active On: NC STOP

Bit 1 A change in the state of the bit changes the polarity of the speed controller's

setpoint voltage (necessary when the axis moves in a direction which is

'mechanically' incorrect).

Active On: RESET

Bit 0 Bit 0 = 1 Start reference point approach with " - " key

Bit 0 = 0 Start reference point approach with " + " key

Active On: RESET

7 6 5 4 3 2 1 0

Bit No.

NC MD

568*

AXIS NAME

Default value

MD T M

5680 0000 0000 0000 0000

5681 0000 0010 0000 0001

5682 0 0000 0010

5683

5709

6–147

SINUMERIK 840C (IA)