GENERAL
A good source for cables is
Machine Tool Services. Their number is 480-985-1941. They can make the motor
and feedback cables to length.
When a machine doesn't
position correctly it can sometimes be because of electrical noise on the MLK
(Machine Lock) signal.
The breakdown on the Fanuc
part numbers is:
i.e. A06B-6079-H203#EM
A06B Identifies part as
either a Motor or an Amplifier.
6079 Identifies Series,
Serial or Digital.
H203 Identifies physical size
and Capacity.
#EM Identifies part
as one approved for the European Community (CE).
It is possible to
troubleshoot with the Ladder even if you have a controller that does not
display it. If you have a hard copy of the ladder, you can follow the instructions
as you normally would by looking for the addresses in the diagnostics. For
example:
-------|
|-------------|/|------------------------------( )------
R551.2
F126.0
Y8.1
All of these can be found
in Diagnostics.
0551 00000X00
= R551.2
0126 0000000X
= F126.0
0008 000000X0
= Y8.1
If the instruction is --|
|-- the corresponding diagnostic bit must be 1 for the instruction to be true.
If the instruction is
--|/|-- the corresponding diagnostic bit must be 0 for the instruction to be
true.
X and Y bits are checked
the same as usual.
This is how a Box works in
the Ladder:
____________________________________
|
| |
|
|
|
SUB |
2 | 3000
| R673 |
--| |---|/|---| 24 |
|
|
|-----------( )----
|
|
|
|
|
|_______|_______|________|____________|
The first block identifies
the box as a fixed timer.
The second block denotes
the timer number.
The third block indicates
the value of the timer in milliseconds.
The fourth block indicates
an address which is acted upon by the timer.
The following is an example
of a M Code box:
______________________________________
| SUB 4 | F151
|
| DEC
|
|
|
|
|
|
|
8411
|
|________|_____________________________|
The first block identifies
the box as a Decode module. F151 is the address where
the M Code is stored and will change with different\M codes. 84 is the M Code
designation (M84). 11 indicates what part of
the M Code is to be decoded in this module
11 = Decode
both High Order and Low Order (8 and 4)
10 = Decode
High Order (8) only
01 = Decode
low Order (4) only
The High Order
can be decoded in one box and the Low Order in another.
The M Code is stored as
BCD. 84 = 10000100
If a controller comes
equipped with RAM chips, they must remain on the memory board. If they are removed, a RAM Parity Error is issued and will not go away even if you hold
RESET/DELETE at power up.
The Fanuc Software Edition
is the big number at the top of the first boot-up screen. Normally something
like O667-****.
If the Absolute Position
display resets to all zeros when the RESET button is pressed, check the MAN/ABS
button. If it is set to MANUAL, the display will reset to zero depending on
parameter settings.
If INCH = 0 on the Setting
page the machine will be in Metric. It will interpret a numerical command as
metric (i.e. G1 X50.0 equals 50mm). The position display will also be in
Metric. If set to 1, the machine will be in Inch. This setting can be changed
at any time, power does not have to be cycled.
One Kbyte of memory is
equal to 1000 characters. When Fanuc sells memory, they sell it by the Kbyte.
They will sometimes talk about memory in terms of Meters.
For most Fanuc controllers
the ON/OFF switches on the CRT/MDI plug into the Input Unit. When you press the
ON button, you are turning on the Input Unit. If everything is OK with the Input
Unit and the controller in general, the Input Unit will latch through itself
and the NC will come on and stay on. If there is a problem in the power
circuits, it will not latch. Depending on the problem it will come on then shut
off or not come on at all. Problems can be diagnosed based on which of these
scenarios occurs.
The Fanuc equivalent to
Mitsubishi Axis Release is Axis Detach.
The drive components of
most Fanuc controllers are the same so the troubleshooting methods, Not Ready
alarm, etc., shown below can be used.
When the main power is
turned on the PSM (power supply module) displays two dashed lines, (steady) the
Servo Amplifier displays a single dashed line, the Spindle Amplifier goes
through it's sequence of displaying it's software information (normally a
string of three) after which it displays two dashed lines (flashing). Now the
NC power is turned on with the E-Stop in. The Spindle Amplifier display stops
flashing, displays the two dashed lines on steady. The PSM and the Servo
Amplifier display do not change. Now the E-Stop is pulled out. The PSM display
goes immediately to 00. The Servo Amplifier display goes immediately to 0. If a
spindle run command is entered such as pressing the CW or CCW Run button or
entering M03, M04 etc., the Spindle display goes to 00 (steady). The spindle
does not run because no speed command has been entered. The spindle speed
setting is reset when power is cycled. If the spindle stop is pressed or Reset,
etc., the Spindle display goes to two steady dashed lines. If the spindle run
and spindle speed command are entered, the display goes to 00 and the spindle
runs. If the E-Stop is pressed, the display goes to two steady dashed lines. If
the NC power is turned off the display goes to 24 and the red LED (ALM) comes
on.
Under normal operation, if
you watch the PSM when the main power is turned off, you will see 02 displayed
briefly and the ALM (red) LED will turn on for an instant.
When a machine is in a NOT
READY state, there are three things to look at.
1. Are the drives and other
control hardware and software ready?
2. Is the E-Stop activated?
3. Is the PMC generating a
Not Ready condition?
If the memory becomes
scrambled or is partially lost, the memory board must be cleared. In most cases
it is only necessary to clear the parameter and offset memory, but sometimes
the program memory must be cleared as well.
The procedure for clearing
the parameter and offset memory is as follows:
1. Turn power to the
controller off.
2. Press and hold the RESET
key.
3. Turn the power back on.
4. Hold the RESET key until
the screen comes up.
5. Release the RESET key.
If the controller will not
come up, repeat the procedure holding the RESET key and the DELETE key while
powering up. Should it ever be necessary to clear only the programs, perform
the procedure holding only the DELETE key. In order to clear the program memory
by powering up with the Delete key pressed, PWE may need to be set to 1.
If you do this you will
lose all programs including the ATC Macro program.
The procedure for
re-entering the parameters varies depending on the media at your disposal.
(i.e. Handy File, PC with Procomm, etc.).
All end users should have
at least one paper copy of the original parameters. If the end user does not
have access to any of the media mentioned above, it will be necessary to load
all of the parameters by hand. This method will take about an hour and require
a lot of key presses. The procedure is:
Pressing and holding the P
key and the CAN key while powering up the controller tells the CNC to ignore
the programmed stroke (soft) limits. The CNC will ignore these limits for as
long it runs until the machine is homed (ZRN). Any time this procedure is used,
for example, to clear an over travel alarm the machine should be zero returned.
A "D" address in
the controllers memory is a location in a data table. A Data Table is an area
of memory set aside by Fanuc for the machine tool builder to store information
to be accessed by the program..
On the SETTING page, making
INCH equal 1 causes the display read in English while zero causes it to read in
Metric. Either way, the actual measuring is not affected.
On some machines turning
the NC power on will cause one or more of the servos to jump as much as
.0003" due to shielding or other power problems. The display will zero
when RESET is pressed.
Never turn off the NC power
while data is being input via RS232. If this is done while inputting a program,
the program memory will be scrambled and will have to be cleared. If you are
communicating with the controller and wish to terminate, it is best to
physically break the RS232 connection.
The maximum allowable
voltage deviation on Fanuc controllers is -15% and +10%. Both the 5vdc and
24vdc outputs of the Power Supply must remain within +/- 5% to prevent an
alarm.
If when trying to
communicate with a Fanuc controller using Procomm, the data flows very slowly,
check the setting for delay between characters and the setting for delay
between lines. Sometimes it is necessary to put a value in one of them in order
to communicate with a Mitsubishi or other controller but it will cause a Fanuc
to slow way down. When working with a Fanuc, these should probably be set to
zero.
The number of data bits for
RS-232 communications on all Fanuc controllers is set at 7 and cannot be
changed.
All communication between
the NC and its I/O boards is serial whether through conventional wiring or
fiber optic connection going all the way back to the 5 and 6 controllers. This
means that if the status bits (Diagnostic or Ladder) show an Input (X) or
Output (Y) going high you can be sure that this is communicated to and/or from
the I/O board unless there is a complete failure of this circuit. In that case
there should be several alarm conditions. If you have a machine on which some
I/O functions operate (LED's, Relays, Switches, etc.) but others do not, either
the I/O board is bad or there is a wiring problem in the wiring between the
board and the devices. Also, be sure to check the power going to the I/O board,
particularly the 24 volts at the six pin connector CDP.
Some inputs, such as Cycle
Start, are not activated when their associated bit goes high but rather when it
goes low after being high. That is, the address tied to the Cycle Start button
is normally low or 0. When the Cycle Start button is pressed, it goes high or
1. If the button is pushed and held nothing happens. Only when the button is
released and the bit goes low again does the cycle start. The importance of
this is that if a machine executes a program on it's own without being
commanded, it can't be caused by a Cycle Start button that is stuck, etc. You
need to look either for an I/O problem which causes the signal to go high then
low or for an internal control problem.
The cable pin outs for a
DB-25 to DB-9 cable to perform DNC operation:
2 ------ 2
3 ------ 3
4 ------ 8
5 ------ 7
6 ------ 4
7 ------ 5
8 ----
|
|----
|
20---
If you get garbage on your
PC when outputting parameters, etc., check the SETTING page to be sure that ISO
= 1.
If a M, S, T alarm occurs
on the CRT check the program to make sure there is not an M06 in it.
If a machine's controller
shuts down at the end of a program or anytime M02 or M30 is executed, check the
Auto Power Off function. This can be either a push button or it may be turned
off and on through the Software Operators Panel. In some cases a Keep Relay may
be assigned to this function.
In rare cases it is
possible for all of the instructions on a rung to be satisfied but the output
coil does not turn on because certain parameters have gotten scrambled.
Typically, the ones scrambled will be those you cannot see so you might try
clearing the memory then reloading the parameters. If you do not have a copy of
the parameters you can backup the ones already in the controller and reload
them by RS-232 or by typing them in. The mere act of clearing the memory may
resolve the problem.
In order to communicate
with a Fanuc controller via an RS-232 port the I/O Channel (Setting Page) must
be set to either 0 or 1. Also make sure you are in MDI mode and that the Edit
Key is on.
Baud Rate Settings:
1 = 50
2 = 100
3 = 110
4 = 150
5 = 200
6 = 300
7 = 600
8 = 1200
9 = 2400
10 = 4800
11 = 9600
12 = 19200
If the Relative position
display zeros when the RESET button is pressed make sure the MAN/ABS button is
in ABS.
For a controller that has
board mounted ROM Never power the controller up with any of the ROM chips off
of the board. Doing so will cause memory loss and scrambled memory. If this
occurs, the memory must be cleared resulting in loss of parameters and
programs. The same is true for replacing the memory back-up batteries. Control
power must be on while batteries are being replaced.
The Macro Executor Cassette
can write information to any part of the CRT. If you see data displayed which
appears abnormal for a Fanuc controller you can try removing the cassette to
see if the data is removed. One example is when OFST flashing and the Offset
page being displayed on a lathe when the tool setter is down.
There is a strange
condition that may arise if the program storage area becomes scrambled. On some
machines if an ATC cycle (M06) is attempted, when the M6 is read in the ATC
program, the controller will delete everything after the M6. This portion of
the program will simply disappear. This condition has only been observed once
to my knowledge and it was resolved by clearing the program storage area.
