Tweco 30 O2 Auto-Cut - Manuel (Page 127)

Manual 0-4818 Auto-Cut 300
2
A-11 APPENDIX
CNC Input / Output Descriptions
E-Stop input— Requires closed connection rated for 35ma. @ 20VDC for unit to operate. Factory installed jumper between
TB1-1&2 must be removing when connecting user supplied E-Stop circuit.
4 Start/Stop input—Switch (momentary or sustained) rating 35ma. @ 20 VDC
Start / Stop circuit configurations. Momentary Start / Stop (Latched) is only available at TB1.
MOMENTARY START / STOP
START / STOP
TB1-6
TB1-5
TB1-4
SUSTAINED START / STOP
START
STOP
TB1-5
TB1-6
Divided Arc Voltage output — Arc Voltage signal is isolated from plasma supply, however (-) is common with other
isolated CNC signals. Max Divided Arc Voltage signal level depends on actual arc voltage times divide ratio however can
not exceed approximately 12 V.
3 Analog Current Control input— This provides a means of remotely setting the plasma’s output current in place of
using the potentiometer, thumbwheel SW or encoder/display on the GCM 1000, GCM 2000 or GCM 2010 gas controls.
It is designed to accept an analog voltage between 0-10 VDC over a 2 wire connection (signal plus return or common)
with 10V equal to the MAX output of the power supply. Like the other CNC signals it is isolated from the plasma supply
using an analog isolation IC but it’s input common “Remote Analog Current Control Ret (-)” is connected to the common
of the other CNC signals such as START, Divided Arc Voltage, etc. The assumption is that this control voltage comes
from an computer analog module. An adjustable power supply or other means of suppling an analog voltage can also
be used. By whatever means the control voltage is supplied, including the computer module, it must be able to be
connected common to the other CNC signals, otherwise an external isolation module will have to be used.
It was not specifically designed to be used to remote a potentiometer but it could work if the pot high is connected to
an accurate external +10 VDC whose common is connected to the pot low and to the Remote Analog Current Control
Ret (-) with the pot’s wiper to Remote Analog Current Control Ret (+). Depending on the length and routing of the wires
from the remote potentiometer it may pick up EMI. Using a shielded cable may be required.
Hold Start input—Normally open, close to hold start. Circuit rating 10 ma. @ 20VDC. Delays pilot ignition, gas
preflow continues. Used for synchronizing starts when multiple plasma supplies are used on same cutting table. User
supplies circuit to keep Hold Start inputs active until all torches have found height.
Preflow On input— Normally open, close to start preflow prior to normal START signal. Circuit rating 10 ma. @
20VDC. Torch Height Controls (THC) normally issue START signal to plasma supply after torch height has been found.
Then the plasma takes 1-2 seconds (or more) to perform preflow before igniting pilot. Some THCs have an output that
can start preflow early during height finding saving 1-2 seconds on each cut.
Pilot On output – Relay contacts rated 1A @ 120 VAC / 28 VDC. Contacts close when pilot on. Can be wired parallel
with Ok to Move contacts to start machine motion when pilot established. Used when starting over holes. Starting over
holes requires setting SW8-1 ON (up) on the CPU PCB for extended pilot time. Using extended pilot time to start over
holes or for cutting over holes will reduce parts life.
OK to Move output — Active when cutting arc is established, arc is transferred. Used to signal cutting table to start
X-Y motion. Relay contacts rated 1A @ 120 VAC or 28 VDC when SW6 set for contacts. When SW6 is set for DCV,
output supplies 15-18 VDC @ 100 ma. May be wired parallel with Pilot On to start cutting machine motion as soon as
pilot established.