Tweco HMC-410 - Manual (Page 59)

HMC-410
July 27, 2005 4-17
4.07 Operation
The HMC-410 may be used in an automatic or
semiautomatic welding configuration. Because of the
different requirements of these two types of welding
processes, the HMC-410 operates differently depending
on how it is used. The following sections will describe
how the control panel operates for automatic and
semiautomatic applications.
The operation discussion will pertain to starting and
stopping the weld, and if configured, executing weld sub
segments. The gas purge and wire feeder inch functions
can be operated on any interface regardless of the control
interface. For example, the front panel INCH button is
always active (if the control is in the ready mode) even if
the auxiliary interface or semiautomatic gun trigger
interface is used.
Automatic Operation
When in the automatic configuration, the HMC- 410 has
various methods of operation. If the unit is to be operated
from the front panel, the control panel would be
considered the master control (slave only to the operator),
and the rest of the equipment (particularly the fixturing)
would be slaved to control inputs from the panel. The
remote pendant operation is very similar to front panel
control, only certain controls of the front panel are
provided on a cable. Conversely, if the unit is to be
operated via the auxiliary interface, then the HMC- 410
becomes a slave to that interface, controlling only the
feeder, power source, and possibly timing. The following
sections will describe these different types of automatic
operation.
Front Panel Operation
When used in a front panel operation, the control panel
will require a weld operator to start and possibly stop the
weld. The proper weld schedule for the work should be
selected or programmed. Front panel controls GAS
PURGE and INCH can be used to test the gas and ready
the filler metal at the torch. Once the welding system and
the work is ready, the weld operator can start the weld by
pressing CYCLESTART on the front panel.
During welding, the front panel will display the segment
it is in and the amount of time in that segment. Also,
during run in, weld, and crater fill, actual arc voltage and
arc current/wire feed speed will be displayed (selectable
on the lower display with the MODE SELECT encoder). If
trim is enabled, the center encoder can be rotated to
increase/decrease arc voltage and the encoder cander can
be rotated to increase/decrease wire feed speed (and thus
current in a CV process).
Termination of the weld cycle will occur when either the
weld time expires (if the weld time is not CONtinuous, a
spot weld) or the weld operator presses CYCLE STOP. If
it is a spot weld, the control may automatically recycle to
another weld cycle if it were so programmed until the last
recycle is done or the CYCLE STOP is pressed. If the front
panel CYCLE START initiated the weld, only the front panel
CYCLE STOP will terminate the weld. This fact is
consistent for the remote pendant and the fixture.
After the weld terminates, the control panel returns to
the ready mode and is ready to start the sequence over
again.
Remote Pendant Operation
As already mentioned, remote pendant operation is similar
to front panel operation. The main point of difference is
that the operator has a pendant to allow him more mobility.
The front panel still provides the display information and
also the capability to trim.
Auxiliary Interface Operation
When the HMC-410 is controlled by the auxiliary inter-
face, it acts as a slave to that interface. In this capacity,
the HMC-410 takes on the role of a power source con-
trol, feeder control, and possibly timing control in the
weld system. Because of this role change, the panel not
only needs to accept commands but send information
back to the auxiliary/ master.
The interfacing to the control panel acts similar to the
front panel type of control. The gas purge control will
cause the panel to close the gas valve, and the feeder
inch control will cause the panel to feed filler metal at the
rate programmed in the run in segment. The auxiliary
start/stop is different from the front panel start and stop
in that both functions are merged into one control. Start/
stop is run in the deadman mode; the control will continue
to weld as long as the control is in start. Once the control
line is not active, the control panel terminates the weld.
Also, the control panel must be in the stopped state before
it can start (for safety).
Also included in the auxiliary control interface is a weld
sub segment advance control, which when enabled (see
Soft Switch description) will cause the weld to change
parameters while in mid-weld. The segments to be
executed may be timed or continuous. If they are timed,
the sub segments will continue with the next sub segment
after time expires. If the sub segments are CONtinuous
timed, the sub segment can change by reissuing the weld
sub segment advance control. Once the sub segment