CHAPTER 4: ELECTRICS 4-20
ALPHA 538/552
f) Feeding pusher control (PLC input A4)
This signal orders the forward movement of the feeding pusher and the bar, independently of the mode of
the lathe clamp.
As long as this signal is present, the signal of the foot switch to open and close the
clamping device of the lathe must be locked. The lathe should not start up in automatic
cycle as long as the clamping device does not grip the bar.
(13) Signals from the bar feeder to the lathe
a) R1 alarm relay
When the bar feeder is in normal operation, the R1 relay signal is energized. In the event of an alarm or
break in the emergency stop circuit, this relay is de-energized.
For safety reason, this signal should bring to a stop all of the axis movements of the lathe as well as the
rotation of the spindle.
When the bar feeder is in alarm mode, the feeding pusher control signal should also de-energize.
b) R3 end of bar signal relay
When the feeding pusher reaches the End of Bar position, relay R3 energizes. This signal is used to
indicate to the lathe that there is not enough material left to make another part. The CNC must jump into a
sub-program to allow the remnant to be dejected.
The operational cycle of relay R3 (pulsed, latched, etc.) is controlled by Services parameters.
c) R4 Automatic mode relay
This signal is present as soon as the bar feeder is in automatic cycle (Aut + Start).
d) Emergency stop button of the bar feeder (EM1-EM2)
When the Emergency Stop button is pressed, the contact opens. The lathe must be in Emergency Stop
mode, and the feeding pusher signal from the lathe must turn off. Two normally closed contacts of the
Emergency Stop button are available for connection in the Emergency Stop circuit of the lathe.
(14) Options
The options described below are an integral part of the standard equipment of the LNS bar feeders.
These signals, however, are not required for the proper operation of the devices, or the safety locking for
protecting persons and materials. The options are available only to optimize production conditions.
(15) Recapitulation of safety instructions related to the interface
· The lathe foot switch for opening the lathe clamping device should not be operational during the
automatic cycle of the lathe.
· The lathe pedal should not be operational as long as the feeding pusher feed command signal is
present.
· Whenever possible, it is advisable to interlock lock the manual command for opening the lathe
clamping device while the feeding pusher command signal is on.
· If the lathe is in the Emergency Stop mode, the bar feeder must also be under the Emergency
Stop mode, and vice-versa.
· If the bar feeder generates an alarm, the lathe must go into alarm mode. The feeding pusher feed
command signal must go off, the spindle axis and rotation must stop.
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