Page 4

Company Profile
Contact Us


This is a very old control which does not have a CRT. Data input is accomplished by scrolling across the LED display with the Address buttons until you are beneath the appropriate code (M, S, T, X, Y, Z, etc.) Once you are under the code letter, use the keypad to enter the desired value and press the Input button.

To check for an Alarm, scroll to ALM. If an alarm is present the corresponding LED will be lit in the Alarm window (OH, OT, etc.)  The OT indicates an over travel condition. With a 5TC control, the power supply for both axes is mounted on the X axis servo amplifier. These amplifiers are DC Servo Units. To see if the power supply is operating properly, check the test points on either unit. Pin 17 should be -15vdc, Pin 16 should be +15vdc, Pin 15 should be +24vdc. All measurements are referenced to Pin 14, 0vdc.

The incoming AC is supplied to the rear of the servo. The MCC contactor is also located here. MCC has a different meaning on the older controls. On the newer controls, MCC is one large contactor which supplies power to all of the servo amps and the spindle amp whenever the control is in a ready state. On this control, each axis and the spindle controller are equipped with their own MCC which may or may not be energized at the same time depending on the state of the NC. Terminals 1 and 2 on the Servo Unit should be about 170-210 VAC while terminals 3 and 4 should be around 100 VAC.

In order to change parameters on the Series 5 you must place the PRM/NOR toggle switch in the PRM position. 

The parameters on a Series 5 are easily scrambled. Look for the software version on the upper IC's on the CPU board. The  software is typically numbered 130,135,153,etc.

The Velocity Control Units (Servos) have a toggle switch to select either 50 or 60 hertz operation.

When the control is operating normally, you should be able to observe the following at power up.

1. Power comes on; after about two seconds the servos are sent the position ready signal (PRDY) 24vdc.

2. Once the servos are ready they send the signal to the NC. You should hear the MCC's energize and stay  
    energized. If they energize and then drop back out there is a problem with one of the servos.

A problem with one servo will disable the PRDY causing the other MCC's to drop out. You can isolate this condition by removing the fuses on the rear of the servo. In most cases these will be 15 amp fuses. The NC is not aware if these fuses are present or not so removing them will prevent the servo from sending a fault signal thereby allowing the control to come up. Even if the fuses are removed while the NC is in a ready state it will remain in a ready state. These fuses may be purchased from Fanuc USA for about $6.00. The part number for the 15 amp fuses is PL4150/SFAB250/402G. Also, these fuses have a contact which close when the fuse is blown. Closing of this contact will prevent the control from coming up but will not generate an alarm. Even momentary closure of this contact will cause both servos to drop out and stay out.

This is very important! If you have a machine that will not come up but the ALARM LED is off as well as the READY LED you almost certainly have either a servo problem or an E-Stop condition.(E-Stop button, Over Travel, etc.) When you have a true servo fault, the ALARM LED will be on and there will be a 1 under SV in the diagnostics. 

The Series 5 control has the capability of storing just one program in battery backed RAM, but it can be a long one ( 10 or 20 meters). This RAM board was an option that most controls were ordered without. If it is present on a control it can be recognized as a board riding "piggy-back" on one of the two main boards.

A Series 5 control has no RS-232 ability, but there are aftermarket devices which will interface with the Tape Reader. The tape readers Baud Rate is 300. 

To return to G Code programming from Conversational programming, press the soft key at the far left of the screen several times. When in graphics, press the PRGRM key on the keypad then use the soft key. Most Spindle functions are controlled by the MTB. They are controlled by affecting the values of the 6000 series parameters and by setting Diagnostic bits.

On a Mazak with a 5M control, if the control skips M Codes or does not execute them properly try replacing one of the I/O modules particularly the M-FIN module.


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.


To monitor the Servo Current on a 10 control you must measure the voltage at pins IR and IS on the servo amplifier. RV1 on this drive is the Gain adjustment. RV3 is the Offset adjustment. You normally will not adjust RV2. You monitor the Servo Error at Diagnostic 3000 and adjust these pots to correct error. To make the best parts especially circles these numbers should be the same. You should first adjust the + and - values to make them equal one axis at a time. Then adjust to X equal Z when doing linear interpolation. If the servo error is out of adjustment you will normally see an ellipse from 45 degrees to 225 degrees or from 275 to 135.

In order to get to the Diagnostics you must:
1. Press the LEFT CHAPTER button. (Beside the soft keys)
2. Press SERVICE.
3. Press DIAGNOS.

To search a program:
1. Select EDIT mode.
2. Press the Left Chapter button.
3. Enter the program number and press FW.SRCH

The Servo Parameters are located in the 1600 to 1800 series.

On a Fanuc 10 control, especially on a Mori-Seiki, the Page function is not immediately obvious. There may be four arrow over buttons. If this is the case, you page up by pressing the two upper cursor buttons at the same time. To page down you press the two lower cursor buttons at the same time.

Also, on a 10 control the PWE is Parameter 8000.0. Go to this parameter and make it 1. The alarm cannot be cancelled with Reset/Cancel.

On a 10 control, the TGM LED indicates a problem on the second axis of a dual amplifier. TGL indicates a problem on the first axis. The TG of the TGL and TGM stands for Tacho Generator. This alarm can also be
caused by a problem with the pulse coder or it's cable. Also is possible for the motor to be shorted or under excessive load, especially if the OV led comes on along with the TGM or TGL.

If on a lathe, for example, you remove the X axis pulse coder connection then turn the power on, the TGL LED will come on. Likewise for the Z axis and TGL.

When working on a 10 control that has no display of the CRT, check the CRT/MDI power supply. This is the bottom board of the CRT/MDI unit. There are three fuses on this board. If the 3.2 amp fuse blows, you will not have any display. Another thing to check is the OPT. INTERFACE board. A problem with the board or the fiber optic cables or the cables reversed will cause no display. In this case, both the Red and Green LEDs on the Main board will possibly be off. If CP21 is disconnected at the time of NC power on, the Green LED will be on as normal but the NC will not be ready and the main board will display A. Under normal conditions when the NC is ready it should display 1. If you have a display of the CRT but it flickers, the CRT/MDI (bottom board) is probably bad. This board is A02B-1001-0160. The top board is A02B-1000-0800. COP1 of the Main board goes to COP3 of the CRT/MDI unit. COP2 of the Main board goes to COP4 of the I/O board. The three fuses on the CRT/MDI are 3.2 amp, .3 amp and .3 amp.

If the Input Unit of a 10 control alarms on power up (Red LED on the Input Unit):

1. Disconnect output connectors (CP3, CP4, CP11, etc.) to determine if the problem is internal or external to the
    input unit.

2. If the alarm does not occur with all connectors removed but occurs if CP11 is connected alone, begin 
    troubleshooting for a problem with the NC power supply or an output of that power supply.

3. The NC power supply can removed from the main board while leaving the cables still connected to it. Try 
    powering up like this. If the alarm goes away, you can assume the problem is with the main board or one 
    of its outputs. Re-install the power supply, remove all cables from the main board and if the alarm does not
    occur, re-connect the cables one at a time until the alarm occurs, then pursue that cable. If the alarm 
    occurred with the   power supply removed from the main board, begin eliminating cables. If the alarm occurs
    with every cable removed except for CP11, the power supply is bad.

A problem in the circuit of CP24 will cause a watchdog alarm. Both the red and the green LED will be on and a C will be displayed. CP14 goes to CP51 of the I/O board.

Fanuc 10 controllers use Keep Relays like an 18 controller.

When changing parameters, they can be changed as individual bits by highlighting the bit. You have to use the arrow keys to move the highlight around.

On a Fanuc 10 control, if the control powers up with a screen which displays: 


2. -
5. -

This means the controller is powering up in IPL mode, the RAM and ROM chips are probably okay but the parameters have most likely been lost or scrambled. In this case, type 99 at the prompt and press the INPUT key. You will be prompted AXIS? At this time, enter the number of controlled axes on the machine and press the INPUT button. You will then be prompted OPTION 01?, at this time you must enter the option parameters 01-032. On the hard copy of parameters, these may be in the form of an eight bit binary number but when manually entered must be in the form of hexadecimal.

When the control is in IPL mode a 0 will be displayed on the Master Board. A 1 is displayed during normal operation.

To send and receive data:
1. Press the PROGRAM soft key.
2. Press the + soft key (right chapter).

The READ and PUNCH soft keys are now shown. If not, look for a TEXT soft key and press it. This should only be necessary id the DIR.MEM soft key has been pressed.

This control has Line Driver and Line Receiver chips like a 0 control. These are soldered to the Main Board. If Fanuc comes in and replaces them they will install sockets so that they can be more easily replaced in the future.

There is a six pin connector on the Input Unit. The connector is labeled CP2. Two of the pins are R and S (220 volts). One pin is ground. Two pins go to a contact in the Power Supply where it is labeled CP11. When the NC power on button is pressed, a relay in the Power Supply is energized. If everything is OK with the power supply, it stays energized. When the button is released, the power stays on.

On most 10M controls, the incoming AC to the NC goes first to the Input Unit via the transformer A80L-0001-0176 terminals A and B (200).These go to terminals R and S on the Input Unit. This transformer has a number of taps on the primary. They are:


Parameter 5220 is the positive stroke limit for X,Y and Z.
5221 is the negative stroke limit.

On a machine with a Fanuc 10M control, the RS-232 cable goes directly to connector CD1 on the top board of the CRT/MDI unit (A20B-1000-0800). This connector is a 20 pin Honda female. On most machines, they use nine of the pins on the control side, ten pins on the machine (25 pin D female) side. Below is the pin information.

Controller side             Machine side ( PC side )

N/C                             1   (PG Protective Ground)
9                                 2   (TD Transmit Data)
8                                 3   (RD Receive Data)
20                               4   (RTS Request to Send)
19                               5   (CTS Clear to Send)
18                               6   (DSR Data Set Ready)
17                               7   (SG Signal Ground)
16                               8   (DCD Data Carrier Detect)
5                                20  (DTR Data Terminal Ready)
14                              25  (BUSY Busy)

Pin 1 on the machine side is connected to the machine ground.

Pin 7 on machine side and pin 17 on Control side are connected to the shield as well as each other.

When data is being input to a 10 or 15 control, it does not flash LSK.

To search a parameter on a 10, 11 or 12 control:

1. Press the SERVICE soft key.
2. Press the PARAMETER soft key.
3. Enter the desired parameter number.
4. Press the INP-NO soft key.
5. Press the INPUT button.

The two manuals necessary to troubleshoot problems on a 10M control are the 10M Maintenance Manual (B54815E) and the 10M Operation Appendix Manual (B54810E).

On controls with a Master Board, particularly a 10M control, a lower case "c" indicates that the board is not communicating with the other boards through the optical link. In this case you will normally find that the green LED on the board (LK2) and the red LED (LK1) will both be on. The status of the LEDs on the I/O board may be green (DC4) is off and red (DC5) is on. As with many other problems on these controls, a power supply could be the culprit. You must check the individual voltages for the proper level. Remember that these voltages have a very tight tolerance. Usually when this alarm state occurs, the outward indication is that the display freezes where it is, pushing any button has no effect.

If the LED display on the Main (Master) board displays what looks like a lower case "c", this is a watchdog alarm. It has several causes but one notable cause is a problem with one or more of the regulated voltages. These are +24v, +5v, 15v and -15v. They can be monitored at test points TJ2, TJ3, TJ4 and TJ5 respectively. The voltage can be monitored at TJ6. Use one of the GND test points instead of the chassis ground for a reference. There is a slight difference in the readings. There are several of these points and they are all common to one another. These voltages must be within a very tight tolerance.

When a control is operating normally, the LED will display "1". LK1 (RED) will be off. LK2 (GRN) will be on. The green LED (DC4) on the I/O board should also be on when things are normal. The red LED is DC5.

The part number of the Power Supply is A16B-1219-0510-01. The part number of the Input Unit is A14B-0076-B001.

The battery pack plugs into the main board at CA6. Its pin outs are:
1 -   + (White)
2 -    - (Black)
3 -   Empty
4 -   Shield
5 -   Empty
6 -   Empty

To toggle between the comments and addresses in the ladder of a 10T control, press the soft key ADDRESS or SYMBOL.


To access the Ladder on an 11 control, press the NC/PC button then press the PCLAD soft key.

Signal Names:

SA   Servo Ready
This signal can be monitored at Diagnostic 500.6 equals 1 when the servos are ready.

A 1 in the LED display on the Master Board of the 11 control means that the control is ready. This does not necessarily mean that the machine is ready, just the control. For example, a problem on the machine side could have an axis interlock turned on so the machine would not be able to move but there would still be a 1 on the display. The interlock signals (i.e. *ITX, *ITY, *ITZ, *IT4) are provide for the OEM to use for various reasons. Many machine builders will tie their ATC ready signal to all of these inputs.

On the 11 control these signals are:

*ITX 400.4
*ITY 402.4
*ITZ 404.4

When working with the Diagnostics on an 11 control be aware that they will differ depending on the type of interface. There are three types:

BMI (Basic Machine Interface)
FS3 (Fanuc System)

To determine which you have check Parameter 2001 Bit 5 and 6.

2001.5 = 0 for BMI
2001.5 = 1 and 2001.6 = 0 for FS3
2001.5 = 1 and 2001.6 = 1 for 6M

To search for a D address:

1. Press NC/PC button
2. Press the PCDGN soft key
3. Type the address (i.e. D33)
4. Press the W Search soft key

The information in these tables is very important. Make sure after a loss of memory that this information is correct. If the value in Address 026 of Control Data Table on an eleven control is wrong, the axes will not ZRN.

To access Data Tables:
1. Press NC/PC button
2. Press PCPRM soft key
3. Press DATA soft key

To do a Ladder search:

1. Access ladder
2. Type in address (i.e. G65.0)
3. Press W search


To release an axis on this control, such as a rotary table make Parameter 0012.7(RMVx) 1. This is a setting parameter. This parameter is only valid when Parameter 1005.7(RMBx) = 1.

PWE on the Fanuc 15 works the same as on a 10 control. Parameter 8000.0 has to equal 1. If this bit will not change, make sure you are on the Setting Page and not the Parameter Page. You cannot change the bit on the Parameter Page unless it has already been changed on the Setting Page.

This can be a little tricky. The best method is:

1. Press the SETTING soft key.
2. Press the CHAPTER soft key.
3. Press the GENERAL soft key.
4. Press the PAGE UP button one time.

On an 11 control as well as an 18, parameter 1850 is the Grid Shift parameter. Parameter 1816 is the reference counter capacity. Parameter 1850 should be set to the value in 1816 or less. If you are trying to adjust 1850 and have trouble make sure 1850 is less than 1816. Also make sure you are adjusting the parameter in the correct direction. For the vast majority of machines where reference return is in the positive direction you must increase the value to shift the axis further away from the decel dog. Sometimes you may reach a point while adjusting where the axis stops responding to small changes in the parameter and after increasing the value a certain amount the axis jumps several millimeters. Again, make sure you are not in a situation where you need to decrease the value rather than increase it. If this is not the case then you may have gone as far as you can go with the Grid Shift and may need to either move the decel dog or the pulse coder. If the reason you
are adjusting this parameter in the first place is because you replaced the pulse coder then, of course, you should look at it first. On most machines the pulse coder will employ a coupling that can only go two ways, either the correct way or 180 degrees out. In this case try removing the pulse coder and putting it back on 180 degrees out relative to the motor. Parameter 1850 is a metric value and the amount that the axis moves is dependent upon the ball screw pitch.

Next Page >>>

<<< Previous Page
Warning and Liability Disclaimer
The information on this and subsequent pages is intended to supplement and reinforce the knowledge of competent machinists and technicians. The authors of this website are in no way lialble for damage or injury resulting from the improper use of the  instructions contained herein.