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18 SERIES CONTROLLER


In order to view and edit 9000 series programs, you must change Parameter 3202.5 (NE9) from 1 to 0.

On most 18 controls, it is very easy to turn on the Custom Macro B option. Simply change Parameter 9933.7 from 0 to 1. The NC will prompt you to cycle the NC power (Alarm 000). This is normal.

To change the PWE on an 18 control:

1.Press the OFFSET/SETTING button.
2.Press the SETING soft key.
3.Cursor to PARAMETER WRITE = 0
4.Enter a 1.
5.Press INPUT button.
6.Press RESET button and CAN button at the same tie to clear alarm 100.

The Option Parameters on an 18 Control can be viewed the same as any other control. They begin at 9900. 

The timers take the form of T numbers.

To completely zero all position displays on:

To reach the Tool Life Management screen on an 18M control, press the OFFSET button then press the RIGHT ARROW button the soft key panel until you see the soft key option then press the appropriate soft key. If this does not work try just pressing the OFFSET button repeatedly until you get to the Tool Life Management screen.

When troubleshooting problems the diagnostics which are equivalent to Diagnostic 700 on a 0 control start at Diagnostic 000.


000    WAITING FOR FIN SIGNAL- An auxiliary function is being executed.
001    MOTION - Travel command of cycle operation is being executed.
002    DWELL - A dwell is being executed.
003    IN-POSITION CHECK - In-position check is being done.
004    FEEDRATE OVERRIDE 0% - Feed rate override is 0%.
005    INTERLOCK/START LOCK - Interlock or start lock is input.
006    SPINDLE SPEED ARRIVAL CHECK - Waiting for spindle speed arrival signal.
010    PUNCHING - Data is being output through reader/puncher interface.
011    READING - Data is being input through the reader/puncher interface.
012    WAITING FOR (UN) CLAMP - Waiting for the end of index table indexing.
013    JOG FEEDRATE OVERRIDE 0% - Manual feed rate override is 0%.
014    WAITING FOR RESET, ESP, RRW OFF - NC is in reset state.
015    EXTERNAL PROGRAM NUMBER SEARCH - Ext. program number search is being done
016    BACKGROUND ACTIVE - Background is being used.

Diagnostics for checking cause of certain alarms:

Details of Alarm 350 Serial Pulse Coder

DGN 0202           7        6          5           4           3           2          1           0
                                   CSA     BLA      PHA      RCA     BZA     CKA      SPH

CSA Hardware of serial pulse coder is abnormal.

BLA Battery voltage is low (warning).

PHA Serial pulse coder or feedback cable is erroneous.

RCA Serial pulse coder is faulty. Counting of feedback cable is erroneous.

BZA  Battery voltage became 0. Replace the battery and set the reference position.

CKA Serial pulse coder is faulty. Internal block stopped.

SPH Serial pulse coder or feedback cable is faulty. Counting of feedback cable is erroneous.

Details of Alarm 351 Serial Pulse Coder

DGN 0203          7        6         5          4            3             2            1           0
                         DTE   CRC   STB

DTE   Communication failure of serial pulse coder. There is no response.

CRC  Communication failure of serial pulse coder.
           Transferred data is erroneous.

STB   Communication of serial pulse coder. Transferred data is erroneous.


Details of Alarm 417 Digital Servo

DGN  0200         7        6        5           4            3            2             1            0
                        OVL    LV     OVC     HCA      HVA       DCA        FBA       OFA

OVL     Overload alarm.

LV        Insufficient voltage alarm.

OVC    Over current alarm.

HCA    Abnormal current alarm.

HVA    Over voltage alarm.

DCA    Discharge alarm.

FBA     Feedback disconnection alarm.

OFA    Overflow alarm.

DGN 0201 Refer to Maintenance Manual for table.

DGN 0204       7         6          5          4            3             2            1            0
                      RAM   OFS   MCC    LDA      PMS

OFS    A/D conversion of current value of digital servo is abnormal

MCC   Contacts of electro-magnetic contactor of servo amplifier is blown

LDM   LED of serial pulse coder is abnormal

PMS   Number of feedback pulses are in error because serial pulse coder C or feedback cable is faulty

To access the Conversational side:

1. Select EDIT mode.
2. Press the PROG button.
3. If the control has conversation, you will see a C.A.P soft key.
4. Either enter a new program number or search an existing one in the usual manner.
5. Press the C.A.P soft key.

If a lathe with an 18T control does not execute a M,S or T function when the block they are in is searched in Auto (Memory) mode, check parameters 3409.7, 3402.6 and 5000 to 5006.

If you have trouble maintaining a constant lead when threading with G92 or G76, check parameter 1626 and 1627. These two parameters affect the accel and the decel of the servos during the two cycles. Often a machine will have a larger value such as 100 which allows you to make good threads only at low rpm like 200 or so. Changing the value to something like 30 or 32 will let you make good threads at close to 1000 rpm.

If the screen turns all green and/or goes blank, the Graphic Card is probably bad. The card plugs into the Main Board.

A standard 18 control has a three slot backplane (Power Supply, CPU, I/O) In order to have the Graphics option, the backplane must have at least four slots. In this case there will be a Graphics card plugged into the chassis.

When working in the ladder of an 18 control, you may not be able to find the Keep Relays listed as K numbers. Often they are listed as PMCS numbers. For example, K5.5 may be listed as PMCS55.

The Ladder of an 18 control can be backed up and restored with a Flash Rom (SRAM) card (PCMIA). If you want to edit the ladder, you will need software from Fanuc. It is called FAPT LADDER III. The price as of 5/3/01 is $1331.00. 

The ladder is designated as Pmc-rb. When it is stored it is done so as a DOS file. In this case it requires an extension. The most common extensions are Pmc-rb.000 and Pmc-rb.txt.

Run Time information etc. can be accessed by pressing the OFFSET SETTING button then the SETING soft key, then page down. The info is:

PARTS TOTAL           =
PARTS REQUIRED   =
PARTS COUNT         =
POWER ON               =     H    M
OPERATING TIME    =     H    M    S
CUTTING TIME         =     H    M    S
FREE PURPOSE       =    H    M    S
CYCLE TIME             =    H    M     S

      DATE =
      TIME =

To access the variables on an 18 control, press the OFST/SETING button twice, if the machine has Custom Macro B there will be a MACRO soft key, press it to view the variables.

The run hours (#3002) reset to 0 after reaching 9544.

Variable 3002 is in one hour increments.

To access the Mirror Image function:

1.Press the OFFSET/SETTING button.
2.Press the SETING soft key.

You will see:

MIRROR IMAGE X = 0   (0: OFF 1: ON)
MIRROR IMAGE Z = 0   (0: OFF 1: ON)

To access the Keep Relays:

1.Press the SYSTEM button.
2.Press the PMC soft key.
3.Press the PMCPRM soft key.
4.Press the KEEPRL soft key.

A useful troubleshooting tool Diagnostic 200. To access it:
1.Press SYSTEM button.
2.Press PMC soft key.
3.Press PMCDGN soft key.
4.Press STATUS soft key.
5.Type D200.
6.Press SEARCH soft key.

The spindle orientation parameter is 4077. This depends on whether the machine uses a Fanuc position coder, magnetic pickup or proximity switch. Normally if a machine uses a proximity switch to orient, the position will not be adjustable by parameter. The switch has to be physically moved.

To access Work Shift:
1.Press OFFSET/SETTING button.
2.Press the + soft key (Right Chapter) twice.
3.Press the W.SHFT soft key.


To cancel the Relative Position:
1.Press the POS button twice or until ACTUAL POSITION Relative is shown.
2.Press U,V or W. The one you pressed will start flashing and some new
   soft key options will be shown.
3.Press the INPUT button or the ORIGIN soft key to cancel position.


If a machine will not execute a program ( automatic operation) and the Cycle Start lamp is not lit, check the following diagnostics:

                      7          6           5           4           3          2          1           0
G0043                                DNC1                             MD4     MD2     MD1

This diagnostic indicates the Mode selected. A 1 means the mode is selected, in this case look for a one at bit 0 unless in DNC mode. If attempting automatic operation during DNC, look for a 1 at bits 0 and 5.

MD1 = Memory Mode

If memory mode is selected with the Mode Select switch, check the mode signal with the PMCDGN.

                      7          6           5           4           3           2         1           0
G0007                                                                          ST

ST = Cycle Start

If the cycle start lamp does not light when the button is pressed, check
G0007.

                       7         6           5           4           3            2         1           0
G0008                                 *SP

*SP = Feed Hold

If the program will not execute when Cycle Start is pressed but the cycle start lamp comes on (status display of CRT shows STRT) check Diagnostics 000-015. Under normal operation, they should all be zero.

000   WAITING FOR FIN SIGNAL
001   MOTION
002   DWELL
003   IN-POSITION CHECK
004   FEEDRATE OVERRIDE 0%
005   INTERLOCK/START LOCK
006   SPINDLE SPEED ARRIVAL CHECK
010   PUNCHING
011   READING
012   WAITING FOR (UN)CLAMP
013   JOG FEEDRATE OVERRIDE 0%
014   WAITING FOR RESET, ESP, RRW OFF
015   EXTERNAL PROGRAM NUMBER SEARCH.

000 WAITING FOR FIN SIGNAL
An auxiliary function (M,S,T or B) specified in a program is being executed and has not finished. Check the diagnostics associated with the auxiliary function.

G0005             7          6         5           4          3             2          1          0
                     BFIN                                        TFIN      SFIN                MFIN

MFIN = M function finish signal
SFIN = S function finish signal
TFIN = T function finish signal
BFIN = 2nd auxiliary function finish signal

F0007              7         6          5           4          3             2          1          0
                       BF                                           TF          SF                  MF

MF = M function strobe signal
SF = S function strobe signal
TF = T function strobe signal
BF = 2nd auxiliary function strobe signal


G0008             7          6          5           4          3             2          1           0
                                              MF3      MF2

MF2 = Second M function strobe signal
MF3 = Third M function strobe signal
The second and third M functions are enabled only when bit 7 of parameter #3404(M3B) is set to 1.

001 MOTION
CNC is reading an axis command in a program and giving the command to the axis.

002 DWELL
CNC is reading a dwell command (G04) in a program and is executing the dwell command.

003 IN-POSITION CHECK
Positioning to a specified position is not completed. Whether or not positioning is complete is determined by the servo position error. Check the position error amount with Diagnostic 300. When an axis is in position, the position error will be almost zero. When the machine is in the commanded position within the IN-POSITION WIDTH amount the positioning is said to be complete. The IN-POSITION WIDTH is set in parameter 1826. If the machine does not position within this window troubleshoot the servo system in accordance with alarm 400, 4n0 and 4n1. Generally speaking, parameter 1826 is for positioning in Rapid Traverse. In cutting feed it is a little more complicated. If parameter 1801.4(CCI) is set to 0, the in-position area for cutting feed is set in parameter 1826. In other words, it is the same as for rapid. If parameter 1801.4 is 1, the in-position area is determined by the setting of parameter 1801.5(CIN).

* If 1801.5 = 0, use the value in parameter 1827 if the next block is also for  cutting feed or use the value in 1826
  if the next block is not for cutting feed.

* If 1801.5 = 1, use the value in parameter 1827 regardless of the next   block. (The setting of parameter 1826 is used for rapid traverse, the setting of parameter 1827 is used for
  cutting feed.

A typical value for parameter 1826 on a machining center is about 20 detection units on all axes. It is also more or less normal for 1826 and 1827 to be set the same. For a turning center, a normal setting might be 20 for 1826 on both axes and about 300 for 1827.

004 FEEDRATE OVERRIDE 0%
Check feed rate override signal at Diagnostics G0012 and G0013.

G0012             7             6             5               4             3             2             1             0
                    *FV7       *FV6       *FV5         *FV4       *FV3       *FV2       *FV1       *FV1

The feed rate override switch generates a binary number which is proportional to the feed rate selected and can be monitored with this diagnostic.


G0013            7              6             5               4              3             2            1              0
                  *AFV7     *AFV6     *AFV5       *AFV4     *AFV3     *AFV2    *AFV1     *AFV0

G0013 is the 2nd feed rate override signal. If the MTB incorporates this function the user can override the feed rate in finer increments. This requires the addition of a second override switch or use of a switch with more contacts.

INTERLOCK/START LOCK
Interlock signal or start lock signal is input.

G0007           7              6              5               4               3             2            1              0
                                                                                                                   STLK

When bit 1 = 1, Start Lock signal is input.

G0008           7              6              5               4               3             2            1               0
                                                                                                                                    *IT

When bit 0 = 0, the interlock signal is input.


G0130           7              6              5               4               3             2            1               0
                   *IT8          *IT7          *IT6          *IT5           *IT4        *IT3        *IT2          *IT1

When one of the bits is 0, the interlock signal is input for the corresponding axis (1-8).


G0132           7              6               5               4               3             2            1              0
                                                                                     +MIT4     +MIT3   +MIT2     +MIT1

G0134           7              6               5               4               3             2            1              0
                                                                                       -MIT4      -MIT3     -MIT2     -MIT1

*MITn   Interlock signal is input for the corresponding axis and direction when the bit is 0. The individual bits do 
             not have the asterisk in their symbol but all eight are active low inputs.


G0124           7              6               5               4               3             2             1              0
                DTCH8     DTCH7     DTCH6     DTCH5     DTCH4   DTCH3   DTCH2    DTCH1

DTCHn   When one of the bits equals 1, the control axis detach signal for the corresponding axis is input. The  
                axis will be in an interlock state because it has been detached.

Also Parameter 0012 (RMVx) This parameter enables the control axis detach function for the corresponding axis.

The axis can be detached by either the CNC or PMC.

The axis detach function for an axis is valid when one of the following bits corresponding to the axis is 1.

F0110              7               6                 5                 4               3                 2                  1                0
                 MDTCH8  MDTCH7     MDTCH6    MDTCH5   MDTCH4   MDTCH3      MDTCH2   MDTCH1

The Axis Detach Function is valid when Parameter 1005.7 is 1.

Also, with regard to the Interlock Function:

Parameter 3003

3003                7               6                5                4               3               2                1               0
                                                                                                             DIT             ITX           ITL

ITL   0 = Interlock signal (*IT) is valid.
ITX   0 = Interlock signal (*ITn) is valid.
DIT   0 = Interlock signal (+/-MITn) is valid.

006 SPINDLE SPEED ARRIVAL CHECK
The CNC is waiting for the spindle speed arrival signal to be input. The spindle has not reached the speed commanded in the program.

G0029             7               6                5                4                3              2                1                0
                                                                            SAR

When this signal is 0, the spindle has not reached the commanded speed.

This function is valid when Parameter 3708.0 = 1.

013 MANUAL FEEDRATE OVERRIDE IS 0% (Dry Run)
Normally, manual feedrate override function is used for jog feed but when the DRN (dry run) signal turns on during automatic operation, override values set with these signals become valid to the following speed set by a parameter.

G0046               7             6                5                4                3              2                 1                0
                       DRN

The Dry Run rate is stored in parameter 1410. It is the dry run rate when the override value is 100%.

The override value consists of 16 bits (2 diagnostics). The diagnostics are G0010 and G0011. If all 16 bits are 0, the override value is 0%. Likewise, if they all are 1, override is 0%.

G0010               7              6                5                4               3              2                 1                 0
                      *JV7        *JV6           *JV5          *JV4         *JV3       *JV2           *JV1          *JV0

G0011               7              6                5                4                 3                2             1                 0
                    *JV15       *JV14         *JV13        *JV12       *JV11       *JV10       *JV9          *JV8


The following table shows the relationship between the bits and the override value:

*JV15                                                                                                                              *JV0      Override value
    1       1       1       1       1       1       1       1       1       1       1       1       1       1       1       1        0.00%
    1       1       1       1       1       1       1       1       1       1       1       1       1       1       1       0        0.01%
    1       1       0       1       1       0       0       0       1       1       1       0       1       1       1       1        100.00%
    0       0       0       0       0       0       0       0       0       0       0       0       0       0       0       1        655.34%
    0       0       0       0       0       0       0       0       0       0       0       0       0       0       0       0        0.00%


014 NC IS IN A RESET STATE

The 18 control is like a Mitsubishi control in that the backlash compensation for Rapid and for controlled feed are treated separately. That is, Parameter 1851 is for G01 backlash comp, 1852 is for rapid.
Generally speaking, a value of 11 or 12 will compensate for about .0005". There is no need to cycle power after changing the parameter. The backlash compensation is ALWAYS applied and in every mode.

To do Background Edit while the program is running
1.Press the (OPRT) soft key.
2.Press the BG-EDT soft key.
3.Press the DIR soft key. (To view the programs)
4.Enter the program number.
5.Press the Cursor down.
6.Edit the program.

When done, press the (OPRT) soft key then the BG-END soft key to go back to the program being run.

When the control is executing a Dwell command, DWL is displayed at the bottom of the screen.

On some 18i controls, the keypad is small and somewhat limited. In this case it may not have buttons for parentheses. You can access the parentheses by changing a parameter. The parameter is 3204.2, once set there will be a soft key for the left parenthesis and one for the right parenthesis when in EDIT mode.

Parameter 4003.0 determines what type of sensor is used for spindle orientation, magsensor, proximity switch, etc.

The following describes observations of a Macome system on a Takumi machine with an 18 controller:

If the magnetic pickup is mounted upside down relative to the magnet, when spindle orientation is commanded the spindle will search back and forth from one side of the magnet to the other across the face of the magnet. If the sensor is moved closer to and further away from the magnet, the distance (number of degrees) that the spindle moves will increase and decrease proportionally. Once the sensor is moved far enough the spindle will rotate continually until alarm 751:FIRST SPINDLE ALARM DETECTION(AL-42) is displayed. AL-42 will be displayed on the spindle amplifier LED display. If the pickup (sensor) and magnet are both mounted upside down, the spindle will behave basically the same thing except that it will search from one side of the magnet through nearly a complete revolution to the other side rather than Just across the face as in the case of the sensor being upside down. I don't know how the machine would behave with the magnet alone upside down. Obviously, when talking about the sensor and the magnet both being upside down, seems to make no sense (they should cancel out) but it does make sense when you consider the North/South pole orientation of the two devices and their movement relative to one another depending upon spindle direction. If the two are upside down, the are fine relative to each other but the approach direction of the poles changes. The bottom line is, the magnet has to be oriented properly relative to the sensor and both must be oriented properly relative to the spindle orientation direction. Normally, if the pre-amplifier, spindle amplifier or cable fails the alarm will occur without the spindle every slowing down or searching. It will behave as if there is no magnet on the spindle at all. There is no adjustment of the control for signal detection level. If the magsensor is disconnected from the spindle amplifier altogether when M19 is commanded the spindle will run at the orientation speed, usually 200 rpm. There will be no alarms, it will just keep running You can monitor the signals output from the pre-amplifier with an oscilloscope. They are five volt pulses whose duration is relative to the rotation speed of the spindle. Below are the pin outs:

  JY3                       AMP

     5    -----------------   A
   14    -----------------   D
     1    -----------------   F
     3    -----------------   E
   12    -----------------   C
7,16    -----------------   B
   10    -----------------   SHIELD

Pin B is the zero volt input from the spindle amplifier, Pin C is the five volt input. Pins D and E are zero volt (common) signals. Pins A and F are the output signals, their phase relationship is important for the proper operation of the circuit. JY3 is a Honda PCR-E20FS connector with a Honda PCS-V20L housing. The pre-amp connector is a Tajimi TRC116-12A10-7M.

On an 18 control if the LCD displays no information, only the backlighting check the small connector that goes from the screen to the video card mounted to the back of the LCD. This connector is hard to see and if it comes loose no information will be displayed.

On the 18 I/O board 24vdc for operating the relays, lamps, etc., is supplied by the machine side. Typically, both the +24 volt and the 0 volt components will come into the I/O board on more than a half dozen pins of each connector (C70, C71, etc.). The Fanuc symbol for the positive side is 24A. The symbol for the negative component is 0V. All of the 0V pins on the board end up at the backplane of the control on check pins GND1 and GND2 which tie to all of the chassis grounds on the control and the drives. Also, these pins tie to several of the pins on each connector on the CPU board such as JA1, JA3, etc.

In order to get the NC Parameters (Keep Relays, etc.) from an 18 control, you must make Keep Relay 17.1 equal 1. Then:

1. Press the SYSTEM button.
2. Press the PMC soft key.
3. Press right CHAPTER button.
4. Press the I/O soft key.
5. Cursor to DEVICE, press the FDCAS soft key.
6. Press the WRITE (PUNCH) soft key.
7. Press the PARAM soft key.
8. Press the EXEC soft key.

If you get alarm I/O OPEN ERROR 20 when you try to output the PMC, it means that the RS-232 cable connection is open.

Sometimes the Baud Rate the control uses for this will be different than the rate it is set for in terms of normal RS-232 functions. For this function it can only be set for either 4800 or 9600. If Keep relay 17.1 equals zero, some of the above soft keys will not be displayed. The Ladder can also be sent in and out this way but it can take as much as an hour. In this case you would press the LADDER soft key instead of the PARAM. Of course, you load the information in the same way you send it out except that you would press READ instead of WRITE. If you have an SRAM disk you can input and output the entire content of the control memory much faster using it.

If you get the alarm "DATA READ ERROR" while inputting the NC Parameters send the file to a text editor and make sure the delete all of the characters on the top line except for the percent sign.

These parameters when viewed with an editor should start with a % (percent sign) then N60000. It should end at about N65000.

On the 18i control you can change the baud rate, stop bits, etc., for transfer of the PMC by pressing the SPEED soft key. This soft key is on the same page with the EXEC soft key. Once this has been pressed, there will be a screen like this:

BAUD RATE   =   2
(0:1200, 1:2400, 2:4800, 3:9600, 4:19200)

PARITY      =   0
(0:NONE, 1:ODD, 2:EVEN)

STOP BITS   =   1
(0:1 BIT, 1:2 BIT)

There is no provision for data bits.  

If you have trouble with the LCD/MDI unit of an 18 control not displaying information check the fuse on the circuit board on the back of the LCD screen This fuse is small and black, it looks more like a shorting pin than a fuse. The newer LCD/MDI unit A02B-0222-C161/TBR is not completely compatible with the older A02B-0222-C151/TBR. That is, if you try to swap only the PCB or the screen from on to the other, bolt hole patterns do not match, etc. If the control issues the alarm "DATA IS OUT OF RANGE" while loading the parameters in from a PC, it means that one or more of the parameters has exceeded it's allowable range. For example many parameters have a setting value from 0 - 32767, no other value is allowed. If you try to enter a value of 50000, for instance, this alarm will be issued. Normally, the control will continue to take the parameters even after the alarm is issued.

The following procedure is for a control that has lost all of its parameters:

Machine must be in E-Stop condition. Once the memory is cleared the control will turn PWE on.

1. Clear the memory (RESET+DELETE while powering up).
2. Load the Option Parameters (9900 - 9990) by hand.
3. Cycle NC power.
4. Set the communication parameters (Baud Rate, etc.) by hand.
5 .Load in the basic parameters (N0000 - N9952).
    a. SYSTEM button
    b. PARAM soft key.
    c. (OPRT) soft key.
    d. Right Chapter button.
    e. READ soft key.
    f. EXEC soft key.
6. Cycle NC power.
7. Load PMC parameters (N60000 - N66999).
    a. SYSTEM button.
    b. PMC soft key.
    c. Right Chapter button.
    d. I/O soft key. The I/O soft key will only be displayed if Keep Relay K17.1 equals 1. On some controls may 
        have to set K900.1 to 1 if the Keep Relays go that high. Normally, they only go to K19.
    e. Cursor to DEVICE.
    f. FDCAS soft key.
    g. Cursor to FUNCTION.
    h. READ soft key.
    i. EXEC soft key.
8. Load Pitch Error Parameters (N1000 - N11023).
    a. Same as basic parameters except you press the PITCH soft key.

To send the basic parameters out of the control, perform item 5, steps a-f except that you press WRITE instead of READ. The same holds true for the other parameters allowing that you will have to press the PUNCH soft key. Also you will have to press either the ALL soft key or the NON-0 soft key depending on whether you want to send out all of the parameters or just the ones which are set to something besides 0. There may be certain advantages at certain times for using NON-0 but generally I would always use the ALL option.

Clearing the control memory (RESET+DELETE) clears all of the parameters and the G. DATA and resets the communication parameters for CH0 to 4800 Baud Rate and two stop bits. It does not clear the C. DATA. Removing the battery and letting the memory die does the same thing as clearing.

To set the display for English on an 18 control make parameter 3102 = 0. Making any of the bits of this parameter = 1 causes the display to be in some language other than English.

Parameter 1815.5 must be set to 1 for any axis that uses an Absolute Pulse Coder.

You can set the keep relay K17.1 in just about any mode as long as the control is in E-Stop condition.

Keep Relay K17.1 causes the STOP soft key to be displayed. This soft key allows you to stop the PLC from executing. Once stopped it can be started again by pressing the RUN soft key.

Machines with turrets which have 18 controls sometimes use values in G DATA. Typically, the value will be a decimal value which is the same as the number of tool stations on the turret. For example, a machine with an eight station turret might have a value of 8 in D0000 of the G DATA. You must be careful when loading in the PMC because this may clear the G DATA. Clearing the memory will definitely clear this data so it is good practice to write these down along with Keep Relays etc. when loading in parameters. Also, doing a memory clear will wipe out the Keep Relays.

To access the G DATA:
1. Press the SYSTEM button.
2. Press the PMC soft key.
3. Press the PMCPRM soft key.
4. Press the DATA soft key.
5. Press the G DATA soft key.

If the commanded spindle speed does not match the actual speed you can try adjusting parameter 3741. You may need to adjust 3742, 3743 or 3743 if the machine has a geared head.

For alarm 751 SERIAL SPINDLE ALARM AL-27 or 750 SERIAL SPINDLE ALARM AL-34 check the Keep Relays. This is particularly true on a machine with more than one spindle such as a live tooling machine since having the Keep Relays set the wrong way can have the control look in the wrong place for the serial terminator.

To delete multiple blocks from a program:
1. Go to the first block to be deleted using the search function.
2. Once there, enter an instruction from the last block to be deleted.
    (This can be any instruction, T-Code, G-Code, etc.)
3. Press the DELETE button. The control will delete from the location of the cursor to the block of the first  
    instance of the instruction you enter just as it goes to the first instance when searching.

When working with a machine which has more than one spindle as in the case of a live tooling machine, the spindles are considered S1, S2 and S3. When working with the spindle parameters you will note the following format.

4077      S1      100
               S2        0
               S3        0

The example above demonstrates how the parameter for spindle orientation position shift appears. S1 is for the main spindle. Typically, the live tool spindle would be S2.

Alarm 151 TOOL GROUP NUMBER NOT FOUND, this alarm is normally issued if a tool number higher than the value set in parameter 6810 (18 control) is called.

Many functions such as axis control, spindle amplifier communication, etc. are performed by modules on the Main Board (CPU). These modules are plugged into Simm sockets. One of these modules controls the CRT. The 40 pin DIP is the system boot software similar to the BIOS of a PC. One of the modules is a FLASH module which typically holds four Intel FLASH chips. This module contains the ladder diagram. In addition, there is a DRAM module which holds the system RAM and a PMC module.

If you want to change the M-Code that operates the parts counter you need to work with parameters 6700 and 6710. If parameter 6700.0 (PCM) equals 0, M02, M30 or an M-Code specified by parameter 6710 will cause
the parts counter to increment. If it equals 1, only the M-Code specified in parameter 6710 will cause the counter to increment. Enter the number of the desired M-Code onto parameter 6710 without the M. Valid numbers are 0-255 but M98 and M99 are not valid.

At CNC power-on, the spindle parameters are sent from the CPU to the spindle amplifier via the serial interface. The parameters are also sent to the amplifier after the spindle alarm 749 has occurred and been reset regardless of the reason for the alarm (spindle amplifier shutdown or signal noise). 

In some cases, if parameter 71.3 is set wrong for the control's software it can cause generation of watchdog alarm 920 when the program is run in graphic mode. The alarm has to do with the control looking for an LSI chip that isn't there.

Parameter 6710 sets the number of the M-Code which increments the Part Counter.

The Servo Tuning screen again using the X axis as an example:

FUNCTION BIT = Parameter 2003
LOOP GAIN = Parameter 1825
TUNING SET = Used by automatic servo tuning function
SET PERIOD = Used by automatic servo tuning function
INTEGRAL GAIN = Parameter 2043
PROP. GAIN = Parameter 2044
FILTER = Parameter 2067
VELOC. GAIN = Parameter 2021 + 256 divided by 256 times 100
ALARM 1 = Diagnostic 200
ALARM 2 = Diagnostic 201
ALARM 3 = Diagnostic 202
ALARM 4 = Diagnostic 203
ALARM 5 = Diagnostic 204
LOOP GAIN = Actual Loop Gain
POSITION ERROR = Actual Position Error (Diagnostic 300)
CURRENT % = Percent of rated value
SPEED RPM = Actual motor RPM

If the Servo Tuning screen is not displayed by pressing the SYSTEM button, right CHAPTER key, SV PARA soft key, then the SV TUN soft key, check parameter 3111 (SVS), it must be 1 for the screen to be displayed.

If need an I/O board with the part number A16B-2202-0721 which is often unavailable, it can be replaced with part number A16B-2202-0720. The only difference is that the 721 has more outputs.

When working with the soft limit parameters for an 18 control, parameter 1320, 1321, etc., a value of 10000 = .4000 inches.

For Alarm 401 check the terminator at JX1B.

On an 18 control to change a Keep Relay the RAM WRITE ENABLE must equal 1.
To do this:

1. Press the SYSTEM button.
2. Press the PMC soft key.
3. Press the PMCPRM soft key.
4. Press the SETING soft key.

You must be in MDI mode and the PWE must be turned on.

If the conditions are not met, the control will display WRITE PROTECT when you attempt to change the Keep Relay.

If a machine with an 18 control continually over travels after being re-gridded you can try this. Change parameter 1860 to 0 then cycle power and zero return re-grid if necessary. I have no idea what this does but it sometimes works. The things that will cause a machine to keep losing it's grid is a crash and looseness.

The Fanuc 18 I/O boards are resistant to shorted outputs so if you have an output on a machine not working, for example, a relay that won't energize, make sure there is no short condition such as a shorted transient diode. In this case the relay will not energize but it will not harm the board. 

If the LCD display is blank, check the Main Board. If the #2 red LED is on, the LCD Unit is probably bad. In some cases the Main Board or the Power Supply may be bad but it is probably the LCD Unit itself. This LED normally indicates that the CPU was interrupted during boot-up but I think a bad LCD will make the Main Board suspect an interrupt.

The option parameter for circular interpolation on a lathe is 9937.0, once this is turned on use G17 along with G02 or G03 for the XpYp plane. Use G18 for the XpZp plane and G19 for the YpZp plane.

You can upload and download the PMC and the LADDER at a baud rate faster than 4800 (up to 19200) by pressing the SPEED soft key and changing the protocol. On this screen you can also change the parity, the stop bits and the write code (ASCII, ISO).

The parameter for the second reference point (G30) for a 16/18 control is parameter 1241.

In order to retrieve data from a variable, you have to execute a macro
program. For example, to find the number of hours the machine has been run (cycle start lamp on). This will only work if the machine has CUSTOM MACRO B.

O3737;
G65 P9100;
M30;

O9100;
#500=#3002;
M30;

The run time data is stored in variable 3002 but can not be directly viewed. This is the only way to access it. After running program O3737, you can go to variable 500 (#500) and read the data.

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.

The feedback from the spindle position sensor, in the case of a 16 or 18 control comes in on connector JY2 or JY4, JY2 for a machine with a built-in spindle. If one of the signals is missing, alarm 750 or 751 will likely be generated. In some instances it can be generated simply by turning the spindle by hand. The important signals are PA1 and PB1. These are sine waves that are out of phase with one another, they should be present when the spindle rotates. PA1 and PB1 are the complements to PA and PB. MZ is the one revolution pulse and MZ1 is it's complement. When alarm 750 or 751 is active, the 5vdc supply to the encoder (sensor) may be removed. Below are the pin outs for JY2:

PIN     SIGNAL

1         MZ
2         MZ1
5         PA
6         PA1
7         PB
8         PB1
9         +5V
12       0V
14       0V
16       0V
18       +5V
20       +5V

Connectors JA7B and JA7A are command cables. JY1 is the output to the load meter.

The parameter to set the Baud Rate on an 18 or 21 control when the I/O channel is set to 0 is parameter 103. The setting value is the same as other Fanuc controls:

1 = 50
2 = 100
3 = 110
4 = 150
5 = 200
6 = 300
7 = 600
8 = 1200
9 = 2400
10 = 4800
11 = 9600
12 = 19200

To set the absolute position on a machine with absolute pulse coders:

1. Move the axes to the desired or required position.
2. Select MDI mode.
3. Set PWE=1.
4. Access Parameter 1815.
5. Set Parameter 1815.4 to 1 for each axis.
6. Cycle NC power.

Anytime this parameter equals 0, the position has been lost and the alarm requesting ZRN will be issued. The battery for the pulse coder is located on the Servo Amplifier. In the case of a dual amp, one battery will hold the position for both axes. The battery is Lithium and not rechargeable. Fanuc recommends that if the power will be off of the machine for a long period you should disconnect the battery. Apparently, the control must disconnect the battery from the pulse coder and power it with the NC power whenever NC power is on.


The Spindle Monitor page of an 18 control displays control signals that are being input and output. For example, when the spindle is in orientation you would see:

Control Input    ORCM      MRDY      *ESP

Control Output   SST       SDT       ORAR

*ESP should always be present during normal operation.

To get to the Spindle Monitor page:

1. SYSTEM button.
2. Right Chapter button.
3. (SP-PRM) soft key.

Even though an axis may appear to be in position according to the position display, it may not be in position as far as the control is concerned. The control's in-position window is very, very narrow. This window is specified by parameter and can be changed but shouldn't be. If an axis pulls high current while at rest, it may not be in position. To check this, go to the Servo Tuning page. On an 18 control:

1. SYSTEM button.
2. PARAM soft key.
3. RIGHT CHAPTER button.
4. SV-PRM soft key.
5. SV-TUN soft key.


Setting Parameters REVX and REVY should both be 0 under normal conditions. When set to 1 the axis direction will be reversed. One condition that can arise from this setting being wrong is that when a program is started and the axis tries to move to the G54 position it may travel until the soft limit is reached. This over travel condition is a result of the mirror image function. Setting the parameter back to 0 will fix the problem but you must perform reference point return after changing the parameter.

When you are loading Parameters or Diagnostics via RS232, you should see LSK flashing after you press INPUT until the control begins receiving the data. Once the data is present at the input of the control, you should see INPUT start flashing.

When Parameter SEQ (On the Setting Screen) is set to 1 the control will insert the sequence numbers automatically.

In order to receive parameters and diagnostics at the PC in text form you must make EIA/ISO = 1 (ISO). 

To copy the ladder to and from a Flash disk you must access the BOOT SYSTEM. This is done by holding the two rightmost soft keys while powering up the NC. When this is done the CNC does not boot.

During a Rapid movement in a program, placing the Feed rate Override switch at 0% will cause axis movement to stop if parameter 1401.4 (RFO) is set to 1. If set to 0, axis movement will not stop.



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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.