NCT Group NCT 990T - Manual (Page 89)

9 Override Switches
89
switch
state
%
1 0
2 1
3 2
4 5
5 10
6 20
7 30
8 40
9 50
10 60
11 70
12 80
13 90
14 100
15 110
16 120
9 Override Switches
The control can operate three override switches:
– the feedrate,
– the rapid traverse, and
– the spindle speed
override switches.
9.1 Feedrate Override Switch
The feedrate override switch has 16 positions. The feedrate switch
determines, by how many percent of the programmed feedrate (F) should
the axes be moved. The diagram beside shows the position of the switch
and the percentage belonging to the position. Position 0% stops the
movement of not only the feed, but also of rapid traverse movements.
In basic configuration feedrate override switch can be selected on
OPERATOR’S PANEL or POSITION screen. After pressing the action
menu key, action
F4 % must be selected. This way the percentage can be
decreased (by means of softkey F–), as well as increased (by means of
softkey F+).
The NCT machine control board is mounted with a
16-position rotary switch. In this case in place of
the above mentioned override adjustment with
softkeys this feedrate switch can be used.
The feedrate switch position is interpreted in jog
mode on the basis of parameter adjustment. If the
value of parameter 1372 JOGFEED is 0, the speed of jog is the modal
value F. If the value of parameter 1372 JOGFEED is 1, the control
registers the speed fixed in table on the basis of feedrate switch position.
(See table of jog mode.)
In the following cases the feedrate switch is ineffective:
– G63, i.e. state of override disabled,
– at the values of variable #3004 listed in programmer’s manual, and
– during thread cutting G33, G34, G76, G78 and tapping cycles G84.1,
G84.
In these cases the control always supposes 100% independent of switch position.