Tweco 400 XT Ultra-Cut Plasma Cutting System With Automated Gas Control - Manual (Page 199)

ULTRA-CUT 400 XT
Manual 0-5306 APPENDIX A-75
The 5 Group relates to CANBUS (Fiber optic) communication errors
501 CANBUS Failure to Acknowledge fault.
The CCM communicates with the gas controls (except GCM 1000 XT) over a fiber-optic cable using the CANBUS protocol. The
CCM is looking for a signal from the gas control (GCM 2010 or DMC) over the fiber-optic link. No signal has been detected.
Communication with the DPC which is relayed through the DMC sets a different code, 301, if there is a problem with it.
Possible causes:
• Gas control is GCM 1000 XT (Auto-Cut 300XT) which has no fiber-optic, with Basic ID problem.
• CANBUS / Fiber-optic problem to either the GCM 2010 or the DMC (part of DFC 3000).
• Control Cable to DMC or GCM 2010 defective.
• Gas control (DMC or GCM 2010) main PCB blown fuse or defective.
• DMC power supply PCB blown fuse or defective.
• CCM defective.
Troubleshooting:
1. GCM 1000XT (also called a Basic Gas Control) does not use CANBUS (fiber-optic) communication. A jumper in the gas
control connector J56 pins 8 & 9, gives the signal “Basic ID” telling the CCM not to expect any CANBUS. If somewhere
this circuit is open, in the Gas Control cable, connector pins, connection from the rear panel GCM connector, J55, to the
CCM (J26) CCM will expect to see a CANBUS connection and report this error because there is no CANBUS connected.
2. DFC 3000. If the gas control does not have power it will not communicate. Check for power to the gas control boards.
a. When using Auto Gas (DFC3000) with DMC & DPC if there is no power to the DMC main board, the green power
light on the DMC front panel will not be lighted. The main board receives several voltages from its separate power
supply board. For communication it needs +5VDC. There is a green LED, D17 (first on the left of the row of LEDs.)
that lights when the main board has +5V power.
b. The DMC power supply board has several blue LEDs that light when it has power. If none of these are on check for
the control cable being connected or the circuit breaker, CB2, on the plasma supply rear panel may be tripped in which
case there is probably a short somewhere.
c. The DMC power supply which supplies several voltages could be missing one or more and still have some blue LEDs
lighted. Check for voltages.
3. GCM 2010.
4. CANBUS / Fiber-optic communication errors can be difficult to troubleshoot, especially when they are intermittent. See
“Test the Fiber” below. Things to look for are:
a. The connectors not locked in place at either end of the fiber.
b. The fiber is damaged or bent sharply. This should not be the case if the fiber is inside the protective hose and the
hose properly secured in the strain relief but that is not always the case.
c. Dirt on the ends of the fiber or in the receiver/transmitter where the fiber plugs in. Blow out gently with clean dry air
such as is used to clean a camera lens.
d. Excessive electrical interference. While the fiber is immune to EMI it can bother circuits at either end. Check that all
the grounding connections are connected per the manual and are clean and tight. Check the resistance of the ground
rod (with all wires disconnected from it). It may have increased due to dryer weather conditions. See the instructions
in the Plasma Installation manual.
e. Defective receiver/transmitter or other circuits on either CCM or Gas Control main board. Otherwise replace either
(or both) Gas Control main board or CCM.