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MAINTENANCE FANUC 6 SERIES CONTROLLER



6 SERIES CONTROLLER


When working on a machine with a Series 6 control it may be set up so that an over travel switch will cause a 400 series servo alarm. In this case, the PRDY LED will be turned off.

There is no keystroke combination to have the NC ignore the soft limits. The values are stored in the 140 to 160 range of parameters.

If the power supply keeps going in to fault status (red LED), you must first eliminate external causes by removing the wires from the 5 and 24 volt terminals. The cause of the fault when the external sources have been removed is almost always the voltage stabilizer. The stabilizer is connected to the power supply by a cable that runs from CP1 on the power supply to CP34 on the voltage stabilizer. If you remove this
cable from either unit before turning the power on, the power supply won't fault. After the power has been on for a while the components will warm up, then you can turn the power off, reconnect the cable and power up again.

Some machines with Fanuc controls, particularly older controls like 5 and 6 controls will use scales on the axes either with or without a pulse coder. On those machines not using a pulse coder they will typically have a tacho-generator for velocity feedback. The scale may be made by a manufacturer such as Heidenhain but often it will be a Fanuc induction scale. These are known as Inductosyn scales and sometimes referred to as resolvers. If the axis has the scale and a pulse coder it is easier to troubleshoot servo and positioning problems. When the axis has a scale, it uses the scale for positioning rather than the pulse coder. So if you have a positioning problem you can detach the scale (parametrically) and use the pulse coder for positioning. If the positioning problem goes away either the scale, its wiring or the Resolver/Inductosyn board is bad. This board conditions the signal from these peripheral devices for use by the NC. In the case of a Series 6 control, this board plugs into the Master Board. Also, in the case of a Series 6, the parameter for removing the scale is P316.0 for the X axis, P316.1 for the Y axis and P316.2 for the Z axis. This is also very useful in troubleshooting axis movement problems such as jerked or rough motion which can be caused by poor feedback. A 1 in the parameter means a scale is used for position feedback, 0 means a pulse coder is used. On the Res/Inductosyn board, you will find a 20 pin Honda connector for each axis. In the case of a three axis machine they are C31 for X, C34 for Y and C37 for Z. You will also find two circular connectors at the bottom of the board for each axis. Referring to the above example, C32 and C33 are for X, C35 and C36 are for Y and C38 and C39 are for Z. The machine can actually be run with the scale detached and using the pulse coder but, of course, will require either Grid Shift adjustment or re-touching of tools. Every control has this ability although the parameter numbers will vary from control to control. When troubleshooting servo problems on an axis such as rough or jerked movement you can swap the command and feedback cables just as you would with a machine using pulse coders. In the case of a machine using a pulse coder for positioning an axis you must swap the command cable which in most cases will be CN1 on the servo amplifier. In addition you must swap the feedback cable which normally runs from the pulse coder to the axes card. The number or name of this connector varies from control to control and also by axis. You have to swap both. Assuming the machine is standard setup such that the all axes have the same pulse coder (resolution, etc.), and the motor directions are set the same the axis swapped with will move when the other axis in the swap is commanded to move. This will allow you to either rule in or rule out either the mechanical or control part of the servo system as the cause of a given problem. In the case of a machine using the scales, the same is true with the exception that there are more cables to swap. You have to swap CN1 as well as the 20 pin Honda connector and the two circular connectors. For example, if you had a problem with the Z axis of a machine you could swap the Z axis with the Y axis. First swap CN1 between the two axes. Then switch C34 with C37. Next switch C35 and C36 with C38 and C39. Anytime you swap cables, make sure you DO NOT REFERENCE RETURN (ZRN) the machine. Obviously, this would cause problems since if the Z axis attempts to reference return, the Y axis will be moving so the Z axis decel switch will never be reached. Another test is to swap the feedback cables at the RES/INDUCTOSYN board and the motor leads at the servo amplifiers. In this case when you give the command for the X axis to move, for example, the Y axis would move, the Y feedback would be sent to the X axis feedback circuits. You will be using the X axis amplifier, axis control board or X axis section of this board and the X axis parameters to control the Y axis. This will eliminate these things as the cause of the problem. Another component to be aware of when these scales are used is a Fanuc board normally found close to the scale reader. This is a pre-amplifier and can sometimes cause problem. The reader is a four wire device. The wires are labeled A, B, C and D. Fanuc calls the reader a slider and sometimes the term will be applied to the complete scale. C31, C33 and C35 are connected to the X, Y and Z sliders. C32, C34 and C36 are connected to the X, Y and Z pre-amplifiers. The RES/INDUCTOSYN board Fanuc number is A20B-0008-0461. The connectors from left to right looking at the front of the board are:

C32  C33  C35  C36  C38  C39

The Tach feedback comes in on the Honda 20 pin connectors C31 for X, C34 for Y and C37 for Z.

On a 6M control if you have certain servo alarms, particularly SV008, you can try to swap just the top board of the drive rather than the entire drive. This can be done by removing only two cables. If you experience new alarms, it may be necessary to change the shorting pins on the boards to make them match how they were before the boards were swapped. This is probably due to a mismatch between either the control or the parameters for that axis and the shorting pin configuration. When this alarm occurs an axis designation will be displayed along with the alarm. The alarm means that the axis position deviated by an amount greater than the value set in parameter 1829 while the axis was stopped (not moving). If the axis position deviates while in motion the parameter where the value is stored is 1828. 

The drives on this control use a single Honda 20 pin connector for both the command and feedback. This cable goes from the drive to the Main Board.

The Grid Shift Parameters for X, Y and Z on a 6M control are 82, 83 and 84 respectively.


6M Controller

If parameter 318.7 is set to 0 the 9000 series programs will be protected and cannot be viewed or edited. If parameter 319.7 is set to 0 the 8000 series programs are protected and cannot be viewed or edited. M-Codes can be attached to specific programs by using parameters 320-332. Certain program numbers are assigned to the parameters, parameter 320 is assigned to program number 9001, parameter 321 is assigned to 9002, etc. The way this works is that, for example, if you assign a value of 70 to parameter 320, when M70 is commanded the control will call up and execute program 9001.

To view the PC parameters on a 6M control that does not have an NC/PC button, press the PARAM button twice then enter the number of the parameter you want to access. Press INPUT. It may be necessary to use put N in front of the number. I.E. N2001. In order to change the value of the parameter you must put a P before the number. I.E. P0 

On machines that will controls such as the 6M which use a spindle amplifier with an orientation board, the IN POSITION LED (LED 6) should be on whenever the spindle is within one degree of it's orientation position. If this LED does not come on after spindle orientation is performed the SPINDLE ORIENTATION COMPLETION SIGNAL will not be output form the CNC. In this case, any function which is waiting for this signal to turn on will not be able to activate. If the spindle is in position but the LED is off you can adjust RV7 IN-POSITION to bring it on.

The axis interlock signals for a 6M control are:

ITX - G96.4
ITY - G97.4
ITZ - G98.4

These are active low signals so a value of 0 will allow axis motion. In the case of a machine that uses hardware inputs to interlock the axes:

ITX - X32.4
ITY - X33.4
ITZ - X35.4

Of course, these are the Fanuc defined and recommended addresses but the machine builder can define their own addresses.

On a 6T control the Backlash Parameters are 115 for X and 116 for Z.

For alarm 087 on 6T control check parameter 310.5 for I/O device 1 or parameter 311.5 for I/O device 2. If set to 1, control codes are not used.  In most cases setting does not matter but in a few it does. 

 310.5 = RSCB1
 311.5 = RSCB2.