3.1 Welding Input/Output Signals
Welding input/output (I/O) signals are used to control welding equipment exclusively via the process I/O printed circuit board during program execution.
The signal numbers for the welding input/output signals (WDI/WDO or AI/AO) are fixed on the welding process I/O printed circuit board, as listed below.
Table 3--1. Welding input signals
Welding input signals
Arc detect Arc detection WI [ 2 ]
Gas fault Gas alarm WI [ 3 ]
Wire fault Wire alarm WI [ 4 ]
Water fault Cooling water alarm WI [ 5 ]
Power fault Power alarm WI [ 6 ]
Voltage feed back Feedback voltage AI [ 1 ]
Current feed back Feedback current AI [ 2 ]
Arc enable Enable welding DI [ 0 ]
Wire stick Wire stick detection WS [ 1 ]
Table 3--2. Welding output signals
Welding output signals
Weld start Arc WO [ 1 ]
Gas start Gas WO [ 2 ]
Inch forward Manual wire feed WO [ 4 ]
Inch backward Manual wire rewind WO [ 5 ]
Wire stick alarm Wire stick alarm WO [ 6 ]
Voltage Command voltage AO [ 1 ]
Current Command current AO [ 2 ]
Wire inch Wire inching AO [ 2 ]
Figure 3--1. Interface for the CA Welding Process I/O Printed Circuit Board
01 02 03 04 05 06 07 14 15 16 17 18 19 20 08 09 10 11 12 13 01 02 03 04 05 06 07 08 09 10 11 12 23 24 25 26 27 28 29 30 31 32 33 34 13 14 15 16 17 18 19 20 21 22 ain 6 ain 6--C ain 3 ain 3--C ain 4 ain 4--C ain 5 ain 5--C aout 1 aout 1--C aout 2 aout 2--C WDI 1 WDI 2 WDI 3 WDI 4 WDI 5 WDI 6 WDI 7 WDI 8 ain 1 ain 1--C ain 2 ain 2--C 0V 0V 0V 0V WDO 1 WDO 2 WDO 3 WDO 4 WDO 5 WDO 6 WDO 7 WDO 8 WDI + WDI -- +24V +24V Printed circuit board
for robot control Process I/O printed circuit board CA
JD1A JD4A JD4B CRM2A CRM2B CRW1 CRW2 Peripheral unit A1 Peripheral unit A2 Peripheral unit Peripheral unit CRW1 CRW2
Welding sequence
Figure 3--2. Welding Sequence (Accompanied by a Motion Instruction)
Robot operation
Operating
At stop
Arc start instruction Arc end instruction Gas start
Gas preflow time Gas postflow time Gas purge time
Weld start Specified voltage
Postprocessing time Specified current
Start--up time Crater prevention time Arc detection
Arc detect time Wire stick detect instruction delay Wire stick detect instruction (WST)
Wire stick detection delay Wire stick detection (WDI+)
(WDI--)
Wire stick detection time
Figure 3--3. Welding Sequence (Not Accompanied by a Motion Instruction)
Robot operation
Operating
At stop
Arc start instruction Arc end instruction Gas start
Gas preflow time Gas postflow time Weld start
Specified voltage
Postprocessing time Specified current
Start--up time Crater prevention time Arc detection
Arc detect time Wire stick detect instruction delay Wire stick detect instruction (WST)
3.1.1 Welding input signals
Welding input signals are supplied from the welding equipment and peripheral units. These signals are specified at the [5 I/O Weld] on the welding I/O screen.
Table 3--3. Welding input signals
Input signal Description
Arc detect WI [2] When the arc detect signal is on, it indicates that an arc is being generated on the torch and welding is in progress. If it turns off during welding, it means that an arc loss occurred. If the arc loss detection function (welding system screen) is enabled, the robot stops immediately when an arc loss occurs, and the program is aborted.
Gas fault WI [3] The gas fault signal is usually connected to the gas output switch. This signal is input when a gas shortage occurs. If the gas shortage detection function (welding system screen) is enabled, the gas fault signal generates a weld alarm.
Wire fault WI [4] The wire fault signal is input if trouble such as a wire shortage occurs in the wire feed unit during welding. If the wire shortage detection function (welding system screen) is enabled, the wire fault signal generates a weld alarm.
Water fault WI [5] The water fault signal is input if trouble occurs in the cooling unit or water circulation hose during welding. If the coolant shortage detection function (welding system screen) is enabled, the water fault signal generates a weld alarm.
Power fault WI [6] The power fault signal is input if a failure occurs in the power supply during welding. If the power supply failure detection function (welding system screen) is enabled, the power fault signal generates a weld alarm.
Voltage feedback AI [1] The voltage feedback signal is an analog voltage signal representing the welding voltage being currently used for welding. It is supplied to the controller. The actual voltage used depends on the specified voltage input scaling factor.
Current feedback AI [2] The current feedback signal is an analog voltage signal representing the welding current being currently used for welding. It is supplied to the controller. The actual current used depends on the specified current input scaling factor.
Arc enable DI [0] The arc enable signal is a peripheral unit input signal for enabling/disabling welding. It works only in the remote mode (when the remote switch on the operator’s panel is set to on). The arc enable signal is used by peripheral units to enable/disable welding. The WELD ENBL key is used with the teach pendant to enable/disable welding. If the signal number is 0, this signal is ineffective.
When the arc enable signal is effective, if the *SFSPD or ENBL input signal becomes off, welding is disabled.
Wire stick WS [1] The wire stick detection signals are fixed on the process I/O board. A wire stick can be detected by reading the voltage across the weld detection circuit (software switch in the controller) when it is operating. A wire stick is judged depending on whether the voltage reading is below a certain level.
3.1.2 Welding output signals
Welding output signals are supplied to the welding equipment and peripheral units. These signals are defined as follows:
Table 3--4. Welding output signals
Output signal Description
Weld start WO [1] When the weld start signal is on, it directs the welding machine to generate arc. Gas start WO [2] When the gas start signal is on, it directs the welding machine to output welding gas. Weld output WO [3] The weld output signal is not in use at present.
Inch forward WO [4] The inch forward signal is used on the teach pendant to direct wire feed. Inch backward WO [5] The inch backward signal is used on the teach pendant to direct wire rewind.
Wire stick alarm WO [6] The wire stick alarm signal is output to the welding machine, if the wire stick detection function is enabled (welding system screen) and a wire stick is detected (when the wire stick detection signal is on). If an automatic wire stick reset is enabled (welding
equipment screen), a wire stick reset is performed a specified number of times. If a wire stick is still detected, this signal is output.
Voltage AO [1] The specified--voltage signal is an analog voltage output signal representing the welding voltage. It is sent to the welding machine. The voltage value of the analog signal depends on the voltage output scaling factor.
Current or wire feed speed AO [2]
The specified--current signal is an analog voltage output signal representing the welding current. It is sent to the welding machine. The wire feed speed signal is an analog voltage output signal representing the speed at which the welding wire is to be fed. It is sent to the welding machine. The output voltage value of the analog signal depends on the current output scaling factor.
NOTE The name of this signal is automatically changed when the model of welding
power supply is set.
WST The wire stick detect instruction signal is used within the controller. This signal is used to operate the weld detection circuit relay in the controller, thereby reading the voltage difference between the wire stick detection signals (WDI+ and WDI--).
Wire inch AO [2] The wire inch signal sets a wire feed/rewind amount when the wire feed/rewind signal is output from the control unit.
Procedure 3--1 Setting welding I/O signals
Step 1 Press the MENUS key. 2 Select 5 (I/O).
3 Press F1 (TYPE).
4 Select “Weld.” The welding I/O signal screen is displayed.
Welding input screen
F1
Weld [TYPE] MENUS 4 ALARM 5 I/O 6 SETUPI/O Weld In G1 JOINT 10 %
1/12
WELD SIGNAL TYPE # SIM STATUS
1 [Voltage ] AI[ 1] U 0.0
2 [Current ] AI[ 2] U 0.0
3 [ ] WI[ 1] U OFF
4 [Arc detect ] WI[ 2] U OFF
5 [Gas fault ] WI[ 3] U OFF
6 [Wire fault ] WI[ 4] U OFF
7 [Water fault ] WI[ 5] U OFF
8 [Power fault ] WI[ 6] U OFF
9 [ ] WI[ 7] U OFF
10 [ ] WI[ 8] U OFF
11 [Wirestick ] WS[ 1] U OFF
12 [Are enable ] [***] * ***
[ TYPE ] HELP IN/OUT SIMULATE UNSIM >
HELP CONFIG SIMULATE UNSIM >
NOTE The analog signal display area of the screen shown above increases or decreases in accordance
with the number of analog input/output signals.
5 To switch between the input and output screens, press F3 (IN/OUT).
Welding output screen
[ TYPE ] HELP IN/OUT
F3
I/O Weld Out G1 JOINT 10 %
1/11
WELD SIGNAL TYPE # SIM STATUS
1 [Voltage ] AO[ 1] U 0.0
2 [Current ] AO[ 2] U 0.0
3 [Wire inch ] AO[ 2] U 0.0
4 [Weld start ] WO[ 1] U OFF
5 [Gas start ] WO[ 2] U OFF
6 [ ] WO[ 3] U OFF
7 [Inch forward ] WO[ 4] U OFF
8 [Inch backward ] WO[ 5] U OFF
9 [Wire stick alarm] WO[ 6] U OFF
10 [Feed forward ] WO[ 7] U OFF
11 [Feed backward ] WO[ 8] U OFF
[ TYPE ] HELP IN/OUT SIMULATE UNSIM >
[ TYPE ] HELP CONFIG SIMULATE UNSIM >
NOTE The analog signal display area of the screen shown above increases or decreases in accordance
with the number of analog input/output signals.
F4
I/O Weld In JOINT 30%
2 Arc detect: WI[ 2] S OFF
[ TYPE ] IN/OUT SIMULATE UNSIM
I/O Weld In JOINT 30%
2 Arc detect: WI[ 2] U OFF
[ TYPE ] IN/OUT SIMULATE UNSIM
7 For forcible output and simulated input/output, place the cursor at ON/OFF, and select the function key.
F4
I/O Weld In JOINT 30%
2 Arc detect: WI[ 2] S OFF
[ TYPE ] IN/OUT ON OFF
I/O Weld In JOINT 30%
2 Arc detect: WI[ 2] S ON
[ TYPE ] IN/OUT ON OFF
NOTE Forcible output or simulated input/output cannot be specified for items having no line number.
WARNING
The controller controls peripheral units using signals. Forcible output or simulated input/output might cause an adverse effect to the safety of the system. Do not use forcible output or simulated input/output before you understand how the signals are used in the system.
Increasing/decreasing the number of controlled analog input/output signals
In the initial state, the number of analog input/output signals that can be controlled is 2 channels. When three or more controlled analog input/output signals are required, the number of analog input/output signals needs to be set.
Two methods of increasing/decreasing the number of controlled analog input/output signals are available.
F A floppy disk that holds welding power supply data including the changed number of analog input/output signals is supplied. Select a welding power supply from the welding power supply selection screen held in the floppy disk data.
For welding power supply data creation, inform FANUC of the following items beforehand: -- Welding power supply name
-- Number of controlled analog input/output signals (AO: 1 to 6, AI: 1 to 6) -- Name and unit of each analog input/output signal
-- Reference value and command value for each analog input/output signal
F The number of controlled analog input/output signals can be increased or decreased by changing the value
Procedure 3--2 Increasing/decreasing the controlled analog input/output signals
Step 1 Turn off the power, then perform a control start. Then, the screen shown below appears.
ArcTool Setup CONTROLLED START MENUS
1/3
1 F Number: F00000
Equipment: 1
2 Manufacturer: DAIDEN
3 Model: UR200/Fe0.8
Press FCTN then START (COLD) when done.
[ TYPE ] HELP
2 Press the MENUS key, then select 4 SYSTEM.
3 Change the setting of the system variable $AWECFG[1].$NUM_AO (number of analog output signals) and $NUM_AI (number of analog input signals) as required.
4 To set the attribute of each analog signal, modify the following system variables in the system variable $AWEPRR[1]:
To change $NUM_AO to 3, and set a frequency (Hz) in AO[3], for example, make the following settings: a Set the value 3 in $AWEPRR[1].$CURRENT_CMD.$PORT_NUM.
b Enter the word FREQUENCY in $AWEPRR[1].$CURRENT_CMD.$NAME (which allows up to 12 characters to be set).
c Enter the word Hz in $AWEPRR[1].$CURRENT_CMD.$UNITS (which allows up to 6 characters to be set).
5 Press the auxiliary key, then select START (COLD).
6 After startup, set a reference value range and command value range for each analog input/output signal on the welding I/O screen. (See the welding I/O screen.)
7 When making a modification to each analog input/output signal, change the following system variables according to $AWEPRR[1].$CURRENT_CMD above:
AO [1] : $ AWEPRR [1]. $ VOLTAGE_CMD AO [2] : $ AWEPRR [1]. $ WFS_CMD AO [3] : $ AWEPRR [1]. $ CURRENT_CMD AO [4] : $ AWEPRR [1]. $ PK_CURR_CMD AO [5] : $ AWEPRR [1]. $ FREQ_CMD AO [6] : $ AWEPRR [1]. $ PULSE_CMD AI [1] : $ AWEPRR [1]. $ VOLTAGE_FBK AI [2] : $ AWEPRR [1]. $ CURRENT_FBK AI [3] : $ AWEPRR [1]. $ WFS_FBK AI [4] : $ AWEPRR [1]. $ FBK4 AI [5] : $ AWEPRR [1]. $ FBK5 AI [6] : $ AWEPRR [1]. $ FBK6
3.1.3 Setting a reference value range and command value range for specifying an analog
input/output signal
Set the correspondence between each analog input/output signal (reference value) of the control unit and an actual output value (command value) of the welding equipment.
Input
Reference value: Voltage of an analog input (feedback) signal sent from the welding equipment to the control unit Command value: Value actually output by the welding equipment for the reference value above
Output
Reference value: Voltage of an analog output signal sent from the control unit to the welding equipment Command value: Value actually output by the welding equipment for the reference value above
Procedure 3--3 Setting a reference value range and command value range for specifying an analog input/output signal
Step 1 On the welding input or output signal screen, move the cursor to an analog signal to be modified. For example, move the cursor to voltage input AI[1].
2 After pressing the F!key, press the F3 (CONFIG) key. The screen shown below appears.
I/O Weld In G1 JOINT 10 %
1/4 1 AI[ 1 ] ^ (Volts) | | * 2 10.000 + - - - * | * | 3 0.000 + - - * | * | | +---+---+---> 4 0.000 50.000 Voltage (Volts )
[ TYPE ] MONITOR VERIFY HELP
3 Move the cursor to a reference value (on the vertical axis) or command value (on the horizontal axis) to be newly set.
The modifiable items are as follows:
F Minimum reference value (lower side on the vertical axis) F Maximum reference value (upper side on the vertical axis) F Minimum command value (left side on the horizontal axis) F Maximum command value (right side on the horizontal axis)
4 By pressing the F3 (VERIFY) key, whether an assigned signal type and number actually exist can be checked.
Procedure 3--4 Changing a welding signal type and number
Step 1 On the welding input or output signal screen, move the cursor to a digital signal to be modified. For example, move the cursor to the Enable Weld signal on the welding input screen.
2 After pressing the F!key, press the F3 (CONFIG) key. The screen shown below appears.
I/O Weld In G1 JOINT 10 %
1/1
WELD SIGNAL TYPE #
1 [Arc enable ] [***]
[ TYPE ] MONITOR VERIFY [CHOICE] HELP
3 To change the signal type:
F Move the cursor to the signal type field.
F Press the F4 (CHOICE) key.
F Choose a desired signal type from WI, DI, and RI, then press the ENTER key. 4 To change the signal number:
F Move the cursor to the signal number field. F Enter a desired number.
5 By pressing the F3 (VERIFY) key, whether an assigned signal type and number actually exist can be checked.
3.1.4 Selecting welder power supply
This screen enables you to load welding power supply data for a welder power supply to be used from internal memory, according to the following procedure.
This procedure saves you the trouble of specifying analog instruction reference values and instruction values, which cannot conventionally be avoided. So, it becomes possible to start welding immediately when the control unit gets started.
The procedure for loading welder power supply data is as follows:
Procedure 3--5 Selecting welder power supply
Step 1 Switch the power off, and perform controlled start. The following screen appears.
ArcTool Setup CONTROLLED START MENUS
1/3
1 F Number: F00000
Equipment: 1
2 Manufacturer: 3 Model:
Press FCTN then START (COLD) when done.
[ TYPE ] HELP
2 Place the cursor at [2 Manufacturer], and click F4 [CHOICE]. Select the manufacturer of the desired welder power supply.
F4
[ CHOICE ]
CONTROLLED START MENUS
1 DAIDEN 5 KOBELCO
2 DAIDEN 6 Lincoln Electric
3 General Purpose 7 NAS
4 KEMPPI 8 -- NEXT --
ArcTool Setup
3 Move the cursor to 3 Model, then press F4 (CHOICE). The options displayed at this time depend on the power supply manufacturer selected in step 2. Examples of screens are provided below.
When the power supply manufacturer is DAIDEN
F4
[ CHOICE ]
CONTROLLED START MENUS
1 UR200/Fe0.8 5 UR350/Fe1.0
2 UR200/Fe1.0 6 UR350/Fe1.2
3 UR200/Fe1.2 7 UR350/Fe1.6
4 UR350/Fe0.9 8 -- NEXT --
ArcTool Setup
When the power supply manufacturer is General Purpose
CONTROLLED START MENUS 1 MIG (Volts, WFS)
2 MIG (Volts, Amps) 3 TIG (Amps)
3.2 Setting the Arc Welding System
For the welding process, the items related to control of the welding machine are specified at the [6 SETUP Weld System] on the system configuration screen.
Table 3--5. Setting arc welding system
ITEMS DESCRIPTIONS
Arc loss Specifies whether to enable/disable the arc loss detection function. If this function is enabled, a weld alarm is issued the arc loss detection time (welding equipment screen) after the arc detection signal becomes off during welding.
Gas shortage Specifies whether to enable/disable the gas shortage detection function. If this function is enabled, a check is made to see whether a gas fault signal is input the gas detection time (welding equipment screen) after the gas start signal becomes on. If the gas fault signal is on, a weld alarm is issued.
Wire shortage Specifies whether to enable/disable the wire shortage detection function. If this function is enabled, a check is made to see whether a wire fault signal is input during welding. If the wire fault signal is on, a weld alarm is issued.
Wire stick Specifies whether to enable/disable the wire stick detection function. If this function is enabled, the wire stick detect instruction signal (WST, internal signal) is turned on to check for a voltage difference between the wire stick detection signals. If there is a voltage difference, an automatic wire stick reset occurs (if enabled), or a weld alarm is issued. If the wire stick detection function is disabled, the automatic wire stick reset function (welding equipment screen) is disabled automatically.
Power supply failure Specifies whether to enable/disable the power supply failure detection function. If this function is enabled, a check is made to see whether a power fault signal is on. If the signal is on, a weld alarm is issued.
Coolant shortage Specifies whether to enable/disable the coolant shortage detection function. If this function is enabled, a check is made to see whether the water fault signal is input during welding. If the signal is on, a weld alarm is issued.
Return to path Specifies whether to enable/disable the return--to--path function. If welding stops due to a hold request or alarm occurrence, the return--to--path function enables restarting welding at the point of break. When directed to restart from a stopped state, the robot moves to the point of break and restarts welding there, provided that welding has been enabled.
Figure 3--4. Return--to--Path Function
1 Welding is stopped, and the robot is moved away.
2 When restarted, the robot moves back through the overlap distance from the point of break, then restarts welding.
Return--to--path speed
Table 3--5. (Cont’d) Setting arc welding system
ITEMS DESCRIPTIONS
Overlap distance When directed to restart, the robot moves back from the point of break through the overlap distance, then restarts welding. This is intended to prevent the sequence of beads from being cut. If the specified overlap distance extends beyond the previous teach point, the actual overlap distance is limited to within that teach point.
Return--to--path speed Specifies the return--to--path speed at which the robot moves to the point of break when restarted.
Scratch start Specifies whether to enable/disable the scratch start (automatic welding error recovery) function. If this function is enabled, and arc is not generated at start of welding, the robot moves in a specified direction through a specified distance. If arc is generated during this movement, the robot moves back to the start point and runs as directed by the program.
Figure 3--5. Scratch Start Function
1 The robot starts moving even if arc is not generated.
2 When arc is generated, the robot moves back for a restart. Return--to--start speed Direction of welding
Scratch start distance
Distance Specifies the distance through which the robot runs in the scratch start mode. If arc is not