Alright: I need some expert advice. I have a 1984 Citizen L16 with a 3T (A?) control with 30M series servo control that is kicking my butt.
I am not an expert but I have the ability to read schematics and to a small degree ladder logic. I have the machine manual with wiring and ladders and the 3T Maintenance manual. I've solved a few problems in the past on my own but this one has me thinking I was just lucky rather than skilled. I am at a stand still on this one;
Symptom 1: X axis started to oscillate and then would ran away to fault (hard overtravel) Had the guys pull the brushes and clean the commutator with no change. manually wound the axis off of the stop. Checked mechanical conditions and everything was OK. While trying to solve that problem the machine went to;
Symptom 2: "Not Ready" with no errors. No MCC.
Diagnostics:
701.5 = 1 = CRST = E Stop, remote reset or MDI Reset turned on.
So E stop right?
Jumpered around the push button.
(This machine is set so that the MDI Estop push button kills everything and only a single push of the Start button should bring the whole thing up including the MCC).
E Stop MDI diag bit responds to button
Ladder says everything is good (all diag bits are correct to drive ESP and EMG coils) but
ESP (from the Machine Tool to the NC) diagnostic bit (101.4) shows 1 (have a note in the original machine manual that says thats correct)
But the EMG (from the "PC" to the Machine tool) (48.6) shows 0 (bad (?))
I can manually drive down the the EMG Machine Tool I/O coil but no change.
PRDY is the Machine Tool I/O coil that turns on the 100V to the Servo unit.
I can manually drive the PRDY relay down and the MCC connects and the hydraulic unit starts but no change in the diagnostics and won't stay latched.
I have wiped and reloaded the parameters and program memory.
I have been through all of the limit switches and no problem there.
I have checked and re-checked power supply(s) output and it is within specs.
I have checked every fuse I can find on the machine
I have pulled the PC boards and all of the PCB connectors looking for bad connections.
I have checked voltages of PCB and Servo board and all appears OK (Fanuc Maint. manual not much help here because it covers all of the Servos that came with the 3T).
The Servo unit has breakers and no fuses.
No errors and no sign of fold-back on PS.
Diagnostic bits for axis OT respond to limit switches.
The OV and OH alarms show when the motors and encoders are disconnected.
I have read the ten pages of hits for "Not Ready" on this board as well as any other source I could find.
Some other diagnostic bit info:
113.7 = 1 = MA = Machine Ready (? )
23.7 = 1 = VRDY = Servo Velocity Control Not Ready (But no Red LED of the Servo Board and no Alarm 2 and the Green LED "VRDY" on the board is lit. I'm assuming since the MCC never made the signal is not making it back to the NC)
129.7 = 0 = ALM Alarm
100.1 = 1 = Interrupt
I am starting to wonder if the ROM is the problem. Not a major problem that generates an error but a scrambled piece of code that makes the machine think everything is OK.
But I can navigate through the screens and low level diagnostics respond to Machine Tool.
The control even energizes the Bar Feed relay coil a second or so after start is pushed and that is way down the ladder (The I/O board appears to be OK as it responds when fuses are pulled).
In the interest of logic I would focus on the Servo unit since symptom 1 would point to it but since I have found nothing wrong with it yet I'm wondering if it was just a result of another problem.
I am starting to wonder if I missed something simple. Shouldn't the PC energize the EMG coil if all of the ladder conditions are met?
I don't mind going back to the beginning and checking everything over again but any advise that points me in the right direction would be greatly appreciated.
And don't be afraid to take me back to the basics because at this point I'm assuming I need it.
Thanks in advance.