Tweco 400 XT Ultra-Cut Plasma Cutting System With Automated Gas Control - Manual (Page 128)

ULTRA-CUT 400 XT
A-4 APPENDIX Manual 0-5306
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 ap-
proximately 12 V.
3 Analog Current Control input— Analog Current Control includes analog isolation module, separate isolation module not usually
required however it’s low input is common with the other isolated CNC inputs. Scaling of Analog Current Control input is 0V =
0A, 10V. = MAX output and is linear in between. However MIN output is 5A. User is responsible for setting correct analog voltage
to maintain at least 5A output. To use Analog Current Control on the I/O PCB set SW 11 to down position and on the CPU
PCB set SW8-2 ON (up).
Hold Start input—Normally open, close to hold start. Circuit rating 10 ma. @ 20VDC. Delays pilot ignition, gas preflow continues.
Used by some height controls to flow gas while finding height. Also 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. Used
with CNC START. Apply START to begin gas flow. Same time apply HOLD to delay ignition until height is found. Remove HOLD
to ignite pilot, initiate arc transfer.
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. PREFLOW ON should remain active for at least 1 second after CNC START is applied. It
is OK if it remains on until the end of the cut. Need to recycle it to begin a new preflow prior to applying START for the next 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 mo-
tion. 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.
5 OK to Move2 – Provides a second set of N.O. contacts that close when arc transfer is detected. Contacts are rated for maximum
of 24 VAC/DC @ 1A. Simplified CNC Circuit.