Pg 3.13 H22
PROBLEM # 3, for P models, disregard all references to a shuttle.
AUTO cycle not being completed.
In the AUTO mode, the PLC controls saw functions through output relays. For a certain function to be
actuated, the PLC must first see specific input(s). Like the output relays, the input relays are located on the
PLC unit. Directly beside input and output terminals are red LED lights, which light up when the corresponding
input is being received or output is being actuated. Observation of these input/output LEDs can help to diagnose
AUTO cycle problems. (See PLC UNIT drawing on page 3.15) When a problem occurs in the AUTO mode, the
lights should be checked to see if they are coming on
at the proper time or at all.
INPUT LED's- If a specific input light does not come on when expected;
- check for a faulty/misadjusted limit switch, push button, encoder or by faulty wiring or
poor connections.
- wiring for each limit switch should be connected from the VDC terminal connection to
particular limit switch, and from the limit switch to the input connector of the PLC.
NOTE: All inputs are denoted by "X"
All outputs are denoted by "Y"
Following is information on output diagnosis and the sequence of inputs and outputs during AUTO cycle.
AUTO CYCLE SEQUENCE: After the mode push button is in the AUTO position and the job has been
Programmed into the PLC, and the Cycle Start push button pressed:
1) Hydraulics running, the head should move to it's up limit, if it is not already there. Shuttle vise should open
and come forward to the home position.
HUP input light must come on for cycle to continue.
HUP input on - cycle should continue, if not check outputs per step 2.
HUP input not on - check that head up limit switch is being actuated, check limit switch / limit
switch wiring.
2) Front vise should be closed, the shuttle vise should stay open and move back to the programmed length;
FVC output should be on and SVO output will light momentarily, REV output and FST output should be on
when the shuttle moves back fast.
3) As the shuttle approaches target length the FST output should shut off and the shuttle should travel slow
for the "Dec. Dist." parameter, cushion distance. (i.e. 1.00") When the shuttle reaches target length, the SVC
output should light, and the shuttle vise should close on the material.
4) FVO output light should come monetarily on and front vise should open.
5) FWD output should light as will as FST for the shuttle to move forward in fast speed. FST will turn off
when the shuttle home cushion period is reached and the shuttle should slow down into the home position.
6) FVC output should light and the front vise should close. FWD light should go out, HDN output should
come on and the head should start to descend for the cut. If blade is not running at this time, auto cycle will
hold until min. SFM is reached. Depending on "Hld Shtl Hm" parameter in the PLC, the shuttle may stay
home and closed during the cut or may move back to pick up the next length. HUP input should go out as the
head descends, and HUP L/S deactivates.
7) After the cut is completed HDN input should light, HDN output should go out, the HUP output should light
and the head should move up. When the head reaches it's up limit, HUP input should come on, RHD output
off and the cycle repeats with the next length being clamped on by the shuttle, front vise opening and the
length being brought forward to home position.
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