Amada WELD CHECKER MM-123A User manual

Y02OM1202869-01
OPERATION MANUAL
Original instructions
WELD CHECKER®
MM-123A

MM-123A
Contents
1
Thank you for your purchase of our Weld Checker MM-123A.
Please read this manual carefully to ensure correct use. Keep the manual handy after
reading for future reference.
Contents
1. Special Precautions ........................................................................................................ 1-1
(1) Safety Precautions....................................................................................................... 1-1
(2) Precautions for Handling ............................................................................................. 1-4
(3) On Disposal ................................................................................................................. 1-4
(4) Warning Labels............................................................................................................ 1-4
2. Features ........................................................................................................................... 2-1
3. Packaging ........................................................................................................................ 3-1
(1) Accessories ................................................................................................................. 3-1
(2) Options ........................................................................................................................ 3-1
4. Name and Functions of Each Section ............................................................................. 4-1
(1) Front ............................................................................................................................ 4-1
(2) Rear............................................................................................................................. 4-5
5. Interface ........................................................................................................................... 5-1
(1) Connection Diagram of the External I/O Signals ......................................................... 5-1
(2) Description of the External I/O Signals........................................................................ 5-3
(3) Connection of Input Signals....................................................................................... 5-11
a. Connection with Device Having a Contact Input (when Using Internal Power Supply) ......................5-11
b. Connection with Device Featuring NPN Open Collector Output (when Using Internal Power Supply).. 5-12
c. Connection with Device Featuring PNP Current Output (when Using External Power Supply) .........5-13
d. Connection with Device Featuring NPN Open Collector Output (when Using External Power Supply) 5-14
6. Installation and Connections ......................................................................................... 6-1
(1) Installing the MM-123A ................................................................................................ 6-1
(2) Preparations for Measurement – Connection between the MM-123A and Sensors.... 6-2
a. Preparing the Toroidal Coil and the Voltage Detection Cable..............................................................6-2
b. Connecting the toroidal coil to the welding machine or arm.................................................................6-4
(3) Grounding the Voltage Detection Cable ...................................................................... 6-5
a. When the welding head is grounded....................................................................................................6-5
b. When the welding head is not grounded..............................................................................................6-5
(4) Connecting the Communication Connector ................................................................. 6-6
7. Basic Operation............................................................................................................... 7-1
(1) Startup ......................................................................................................................... 7-1
(2) Basic Usage of the MM-123A ...................................................................................... 7-2
a. C.ANGL (conduction angle) Mode .......................................................................................................7-2
b. COUNT (count) Mode ..........................................................................................................................7-2
c. SCH (schedule) Mode..........................................................................................................................7-3
d. STATUS (status) Mode........................................................................................................................7-4
e. PRG (program) Mode ..........................................................................................................................7-4
(3) Preparation for Measurement...................................................................................... 7-6
a. Selecting the Current Measurement Mode ..........................................................................................7-6
b. Selecting the Schedule Number to Set ..............................................................................................7-10
c. Selecting Peak or Effective Value of Current .....................................................................................7-11
d. Selecting the Current Range..............................................................................................................7-12

MM-123A
Contents
2
e. Selecting Peak or Effective Value of Voltage .....................................................................................7-13
f. Selecting the Voltage Range .............................................................................................................7-14
g. Setting the Measurement Start Time (FIRST) and the Measurement End Time (LAST) ...................7-15
h. Selecting TP/TH (in the current measurement mode CAP-S and CAP-L only)..................................7-18
(4) Upper/Lower Limit Judgment Function ...................................................................... 7-20
a. Setting the Upper and Lower Limits of the Current ............................................................................7-20
b. Setting the Upper and Lower Limits of the Voltage ............................................................................7-22
c. Setting the Upper and Lower Limits of the Weld Time .......................................................................7-24
(5) Settings in the Program Mode ................................................................................... 7-26
a. Setting the Preset Counter (COUNT).................................................................................................7-26
b. Setting the Step Counter....................................................................................................................7-27
c. STATUS Setting ................................................................................................................................7-29
d. Difference between the Original Mode and the ISO17657-compliant Mode ......................................7-30
e. Setting the Various Levels .................................................................................................................7-32
f. Impulse Measurement .......................................................................................................................7-34
g. Communication Setting......................................................................................................................7-36
h. System Setting...................................................................................................................................7-39
i. Setting the Upper/Lower Limit Judgment when Using the Step Counter Function.............................7-44
j. Password Setting ...............................................................................................................................7-46
(6) Checking Settings and Initializing.............................................................................. 7-48
a. Checking the Setting and the Previously Measured Value ................................................................7-48
b. Initializing the Schedule Setting .........................................................................................................7-49
8. Data Communication ...................................................................................................... 8-1
(1) Data Transfer............................................................................................................... 8-1
(2) Configuration ............................................................................................................... 8-1
(3) Communication Protocol (Single-Directional Communication) .................................... 8-5
a. Monitor Data ........................................................................................................................................8-5
b. Error Data ............................................................................................................................................8-9
(4) Communication Protocol (Bi-Directional Communication)......................................... 8-10
a. Reading the Monitor Data ..................................................................................................................8-10
b. Reading and Writing the Upper and Lower Limit Value Data of Current ............................................8-12
c. Reading and Writing the Upper and Lower Limit Value Data of Current of Each Step.......................8-14
d. Reading and Writing the Upper and Lower Limit Value Data of Voltage............................................8-19
e. Reading and Writing the Upper and Lower Limit Value Data of Voltage of Each Step ......................8-21
f. Reading and Writing the Upper and Lower Limit Value Data of Weld Time.......................................8-25
g. Reading and Writing the Upper and Lower Limit Value Data of Weld Time (TP/TH) .........................8-28
h. Reading and Writing the System Setting Data...................................................................................8-30
i. Reading and Writing the Counter Data of Each Step.........................................................................8-34
j. Reading and Writing the I/O Setting Data ..........................................................................................8-36
k. Reading and Writing the Communication Setting Data ......................................................................8-38
9. Fault Code List ................................................................................................................ 9-1
10. Specifications ................................................................................................................ 10-1
(1) Measurement Specification ....................................................................................... 10-1
(2) Specification of the MM-123A.................................................................................... 10-5
11. Calibration...................................................................................................................... 11-1
12. Outline Drawing............................................................................................................. 12-1
(1) Body .......................................................................................................................... 12-1
(2) Drawings for Mounting Bracket.................................................................................. 12-2
a. Front and Rear Mounting ...................................................................................................................12-2
b. Right and Left Mounting.....................................................................................................................12-2
Index............................................................................................................................................1
EU Declaration of Conformity

MM-123A
1. Special Precautions
1-1
1. Special Precautions
(1) Safety Precautions
Before using the weld tester, please read through the Safety Precautions carefully to
ensure proper use.
The precautions listed here are designed to ensure safe use and proactively prevent
risks and damage to the user and other people. All precautions are critical for safety.
Please read them all.
The hazard signs have the following meanings:
Mishandling may cause imminent risk of death or serious
injury.
Mishandling may cause risk of death or serious injury.
Mishandling may cause risk of injury and physical
damage.
These signs represent “DON’Ts.” They warn of actions not
covered by the product warranty” in the previous
document.
These signs represent “DOs" which must be observed by
the product user.
A sign within a triangular border indicates that a hazard
(danger, warning or caution) is present.
DANGER
WARNING
CAUTION

MM-123A
1. Special Precautions
1-2
NEVER ATTEMPT to disassemble, repair or modify the instrument.
Do not touch any parts inside the instrument. Failure to observe this may result
in an electric shock or fire.
For battery replacement, inspection or repair, please contact your dealer or us.
NEVER burn, destroy, cut, crush or chemically decompose the
instrument.
This product incorporates parts containing gallium arsenide (GaAs).
DO NOT place your hands between the electrodes.
When welding, be extremely careful not to get your fingers or hand caught in the
electrodes.
During or immediately after welding, DO NOT touch the welded areas or
electrode.
The welded areas of the workpiece, the electrodes and the welding machine’s
arm are extremely hot. To prevent burns, do not touch these areas.
Ground the instrument.
If the instrument is not grounded, you may receive an electric shock in the event
of malfunction or current leak. Be sure to perform grounding work.
ALWAYS use the specified power supply.
Failure to use the power supply specified in the Operation Manual may result in
a fire or electric shock.
Use the specified cables and connect them securely.
Failure to do so or improper connection may result in a fire or electric shock.
Keep the power and connection cables free of damage.
Do not walk on, twist or tug the cables.
Damaged cable may result in an electric shock, short circuit, or fire.
For repair or replacement, contact your dealer or us.
In the event of an anomaly, STOP the operation.
Continuing the operation with anomalies such as a generation of fumes, a
burning odor, strange noise, or overheating unattended may result in an electric
shock or fire. In the event of the above or other anomaly, immediately contact
your dealer or us.
STAY AWAY from the instrument if you have a pace maker.
If you have a pacemaker, do not approach a welding machine in operation or
the immediate area unless your doctor has given consent.
Welding machines generate a magnetic field which interferes with the operation
of a pacemaker.
ALWAYS wear appropriate work clothing.
Wear protective gear such as gloves, a long-sleeved top and leather apron.
Surface flash and expulsion can cause burns if it contacts the skin.
DANGER
WARNING

MM-123A
1. Special Precautions
1-3
ALWAYS wear protective goggles.
Directly looking at surface flash and expulsion during welding can temporary
impair vision. Welding spatter can cause permanent eye damage, including
blindness.
DO NOT splash water.
Electrical parts may cause an electric shock or short circuit if they become wet.
Keep the area clear of flammable objects.
Surface flash and expulsion generated during welding may ignite flammable
objects, resulting in a fire. If work involves use of flammable items, place a
non-flammable cover over such items.
DO NOT cover the instrument with a blanket or cloth.
During operation, do not cover the instrument with a blanket or cloth. This may
lead to the instrument overheating and catching fire.
Install the instrument on a firm and level surface.
Injury may result if the equipment falls or is dropped.
Do not sit on or place objects on the instrument.
Failure to observe this precaution may lead to malfunction.
Wipe off dust from the power plug and securely insert it all the way.
Dust or improper insertion may lead to the plug heat up and catch fire.
Hold the power plug when removing or inserting it.
Removing the power plug by pulling on the cable may damage the power cable,
resulting in an electric shock or causing the cable to catch fire.
If you do not use the instrument for extended periods, remove the power
plug from the outlet.
Failure to do so may deteriorate the insulation, resulting in an electric shock,
current leakage or fire.
Provide fire extinguishers.
Provide fire extinguishers at the welding site as a precautionary measure.
Perform maintenance and inspection on a regular basis.
Perform maintenance and inspection regularly and repair damaged areas and
parts before using the instrument.
Wear soundproof earmuffs.
Loud noise may impair hearing.
CAUTION

MM-123A
1. Special Precautions
1-4
(2) Precautions for Handling
■Avoid the following locations when installing the instrument:
•Humid (above 90%) locations
•Extremely hot (above 45°C) or cold (below 0°C) locations
•Location where variation in environmental temperature is large
•Near a high noise source
•Location where chemical substances, etc. are handled
•Location where condensation occurs
•Dusty location
•Location exposed to direct sunlight
•Location that is inclined, insecure, unstable, or weak
■Check the voltage and power frequency before installation.
■Keep the exterior clean with a soft cloth or cloth lightly dampened with water.
For stains, clean them off using a diluted neutral detergent or alcohol. Do not
use thinner or benzene as they may cause discoloration or deformation.
■To prevent malfunction, do not allow any foreign objects such as screws or
coins to enter the instrument.
■Operate the instrument according to the procedure described in the Operation
Manual.
■Operate the switches and buttons with care. Rough operation or the use of a
tool or pen tip may result in damage or malfunction.
(3) On Disposal
This product incorporates parts containing gallium arsenide (GaAs). At the time
of disposal, separate it from general industrial waste or domestic waste and carry
out the disposal in accordance with applicable laws and regulations.
(4) Warning Labels
A warning label is pasted on the instrument for safe use. The pasting place and
meaning of each label are as shown below.
注 意
CAUTION
CONNECT GROUNDING WIRE.
アース線を接続する事
注 意
DO NOT OPEN COVER.
TOUCHING THE INSIDE
MAY CAUSE AN ELECTRIC SHOCK.
CAUTION
感電の恐れあり
カバーを開けるな
Pasting place: Top cover
Meaning: Caution for
grounding wire
connection
Pasting place: Top cover
Meaning: Danger of
electric shock

MM-123A
2. Features
2-1
2. Features
The Weld Checker MM-123Ais a measuring instrument for monitoring the resistance
welding.
The MM-123Acan measure and display the welding current, voltage between electrodes,
and weld time. The MM-123Aenables quality control in welding.
The MM-123Ahas the following features.
•Compact body
The outline is 187 x 70 x 248 (mm) and the weight is approx. 2 kg. The MM-123Acan be
installed anywhere and can be carried easily.
•Supports a long-time welding current
The maximum measurement time is 3000 ms (150 CYC : 50 Hz). A long-time welding can
be measured compared with 2000 ms (100 CYC : 50 Hz) of conventional models.
•ISO17657-compliant measurement
In addition to the arithmetic mean RMS which is a conventional calculation system, the
RMS in a whole current flow time which is the ISO17657-compliant calculation system can
be selected by using the ISO-compliant toroidal coil (MB-400M and MB-800M).
•Voltage measurement between electrodes
By using the voltage detection cable (option), welding current and voltage between
electrodes can be measured simultaneously. To measure voltage, the relay cable (option)
is required.
•Managing measurement data with PC or server
You can transmit measurement data to your PC or server through the Ethernet
communication.
•Applicable to various welding currents
The MM-123Ais applicable to any welding machine.
•Upper/Lower limit judgment function provided
When the measured value is outside the preset value, the trouble signal is output. This
function is provided for quality control purpose.
•Applicable to various power supplies
The MM-123Acan be used with 100–240 V AC power supply. Also, the MM-123Acan
be operated with 24 V DC, allowing a variety of application.
•Easy operation with a button
All operations are done with a switch. Operation is easy since there is not buttons and
switches on the panel.
•Easy-to-see LED display
Bright and clear 7-segment LED is employed. You can see characters on the display
clearly from any angle.
[List of applicable welding currents]
・Single-phase-AC ・Transistor
・DC-inverter ・Capacitor
・AC-inverter

MM-123A
3. Packaging
3-1
3. Packaging
(1) Accessories
Item Model No. Q’ty
I/O connection
connector
Case DX-50-CV1 1
Connector (50 pins, male) DX30A-50P(50) 1
Ferrite core*1 ZCAT3035-1330 1
Operation manual AS1202873 1
(2) Options
Item
Model No.
Item No.
Power cable*2 (3 m)
KP-35 KS-16A SVT#18x3 B-TYPE
(3-pin plug, for 100-120 V AC) 1153158
KP244 VCTF3*1.25 KS16D 3M gray
(Japan, for 200 V AC) 1157798
CEE3P-W-1.8
(Round plug, for 200-240 V AC) 1024118
3-pin/2-pin conversion
adapter for power cable KPR-24 (for 100-120 V AC) 1025303
ISO toroidal coil*3
MB-800M(approx. 250 mm in dia.)
1x sensitivity coil (with 800 mm bracket)
(cable length 3 m)
1192501
MB-400M(approx. 120 mm in dia.)
1x sensitivity coil (with 400 mm bracket)
(cable length of 3 m)
1192500
ISO toroidal coil
extension cable*4
SK-1194039 (2 m) 1194039
SK-1194040 (5 m) 1194040
SK-1194041 (10 m) 1194041
SK-1194042 (20 m) 1194042
Voltage detection cable*5 SK-1205023 1205023
Relay cable*5
(for branching current and
voltage)
SK-1201740 1201740
LAN cable (3 m) KB-FL6A-03BL 1203030
I/O conversion cable*6 SK-1205384 1205384
Bracket (for fixing on table.
2 pieces required.) Z-02414-001 1032596
*1: Pass the LAN cable through this twice.
*2: Exclusively for the MM-123A. Do not use for other devices.
*3: The MM-123A is exclusively for the ISO toroidal coil. Do not use with other
toroidal coils.

MM-123A
3. Packaging
3-2
*4: For extending the MB-400M/800M.
*5: For simultaneously measuring current and voltage, the relay cable (for
branching current and voltage) is required.
*6: For converting the I/O connector dedicated for the MM-122A.

MM-123A
4. Name and Functions of Each Section
4-1
4. Name and Functions of Each Section
(1) Front
①ISO17657-compliant
mode LED
②Current display
③Current upper/lower limit
judgment LEDs
④Voltage display
⑤Voltage upper/lower limit
judgment LEDs
⑥Weld time display
⑧Mode display
⑦Weld time upper/lower
limit judgment LEDs
⑪No-current LED
⑫Peak current
measurement LED
⑬Effective current
measurement LED
⑭Current peak/effective
selection LED
⑮Current range selection
LED
⑯Peak voltage
measurement LED
⑰Effective voltage
measurement LED
⑱Voltage peak/effective
selection LED
⑲Voltage range selection
LED
⑨Mode selection LEDs
⑳Weld time (ms) LED
㉑Weld time (CYC) LED
㉒TP/FIRST (measurement
start) LED
㉓TH/LAST (measurement
end) LED
⑩Operation button

MM-123A
4. Name and Functions of Each Section
4-2
 ISO17657-compliant mode LED
Lights up when the ISO17657-compliant mode is selected.
When this LED lights up, the measurement result calculated with the
measurement method complied with ISO17657 is displayed in the effective
value measurement.
Current display
Displays the selected measurement results of the current (peak or effective
value) and the set value for the current upper/lower limit judgment.
Current upper/lower limit judgment LEDs
Indicate the result of the current upper/lower limit judgment. There are three
LEDs, UPPER, GOOD and LOWER.
UPPER (red)
lights up When the measured current is higher than upper limit.
GOOD (green)
lights up
When the measured current is the upper limit or lower and
the lower limit or higher.
LOWER (red)
lights up When the measured current is lower than lower limit.
Voltage display
Displays the measurement results of the selected voltage (peak or effective
value) and the set value for the voltage upper/lower limit judgment.
Voltage upper/lower limit judgment LEDs
Indicate the result of the selected voltage upper/lower limit judgment. There
are three LEDs, UPPER, GOOD and LOWER.
UPPER (red)
lights up When the measured voltage is higher than upper limit.
GOOD (green)
lights up
When the measured voltage is the upper limit or lower and
the lower limit or higher.
LOWER (red)
lights up When the measured voltage is lower than lower limit.
Weld time display
Displays the measurement results of the weld time and the set value for the
weld time upper/lower limit judgment. The unit for the weld time is CYC or ms.
Weld time upper/lower limit judgment LEDs
Indicates the result of the selected weld time upper/lower limit judgment. There
are three LEDs, UPPER, GOOD and LOWER.
UPPER (red)
lights up When the weld time is higher than upper limit.
GOOD (green)
lights up
When the weld time is the upper limit or lower and the lower
limit or higher.
LOWER (red)
lights up When the weld time is lower than lower limit.
When the green LED (GOOD) lights up, the [GOOD] signal is output.
When the red LED (UPPER or LOWER) lights up, the [NG] signal is output.
Mode display
Displays the setting items, such as conduction angle, counter value, schedule
number and status.

MM-123A
4. Name and Functions of Each Section
4-3
Mode selection LEDs
Data for the mode whose LED is on is displayed on the mode display. Turn the
operation button to select a mode. For details, see [7. (2) Basic Usage of the
MM-123A].
Operation button
For all operations. This button can be pressed and turned right and left.
(Note) When operating the operation button, an LED not selected may light up
for a moment. It is not malfunction.
○
11 No-current LED
Lights up when the welding current has not flowed (no-current), and the [NG]
signal is output. To use the no-current judgment function, the [NO CURR]
signal must be input. For details, see descriptions of Pins 12, 13, 25, 45, and
46 in [5. (2) Description of the External I/O Signals].
○
12 Peak current measurement LED
Lights up when the peak current measurement is selected. When this LED is
on, the current is displayed as the peak value.
○
13 Effective value of current measurement LED
Lights up when the effective value of current measurement is selected.
When the ISO17657-compliant mode LED is on, the current is displayed as the
effective value in the ISO17657-compliant mode.
When the ISO17657-compliant mode LED is off, the current is displayed as the
effective value in the original mode.
○
14 Current peak/effective selection LED
Lights up to select the current to be measured from peak and effective value in
the program mode.
○
15 Current range selection LED
Lights up to change the current range in the program mode.
○
16 Peak voltage measurement LED
Lights up when the peak voltage measurement is selected. When this LED is
on, the voltage is displayed as the peak value.
○
17 Effective value of voltage measurement LED
Lights up when the effective value of voltage measurement is selected.
When the ISO17657-compliant mode LED is on, the voltage is displayed as
the effective value in the ISO17657-compliant mode.
When the ISO17657-compliant mode LED is off, the voltage is displayed as
the effective value in the original mode.
○
18 Voltage peak/effective selection LED
Lights up to select the voltage to be measured from peak and effective value in
the program mode.
○
19 Voltage range selection LED
Lights up to change the voltage range in the program mode.
○
20 Weld time (ms) LED
Lights up when the weld time is selected in ms.
○
21 Weld time (CYC) LED
Lights up when the weld time is selected in cycle.
○
22 TP/FIRST (measurement start) LED
Lights up to set the measurement start cycle (or start time) in the program
mode. For details, see [7. (3) g. Setting the Measurement Start Time
(FIRST) and the Measurement End Time (LAST].
If this LED is on in the current measurement mode CAP-S or CAP-L, the TP
(time peak) time is measured. For details, see [7. (3) h. Selecting TP/TH (in
the current measurement mode CAP-S and CAP-L only)].
○
23 TH/LAST (measurement end) LED
Lights up to set the measurement end cycle (or end time) in the program mode.
For details, see [7. (3) g. Setting the Measurement Start Time (FIRST) and
the Measurement End Time (LAST].

MM-123A
4. Name and Functions of Each Section
4-4
If this LED is on in the current measurement mode CAP-S or CAP-L, the TH
(time half) time is measured. For details, see [7. (3) h. Selecting TP/TH (in the
current measurement mode CAP-S and CAP-L only)].

MM-123A
4. Name and Functions of Each Section
4-5
(2) Rear
⑥Toroidal coil/voltage
detecting connector
①LAN cable connector
④Power cable
connector
③External I/O
connector
②Service connector
⑤Grounding
terminal
⑦Power supply switch
⑧Fuse holder

MM-123A
4. Name and Functions of Each Section
4-6
LAN cable connector
For connection with the LAN cable for the Ethernet communication.
Service connector
Do not connect anything.
External I/O connector
For connection with input and output signals from peripheral devices.
Power cable connector
Connects to the power cable (option) when the single-phase AC power supply
(100–240
V) is used.
Grounding terminal
Use this terminal for grounding when the power cable with a grounding wire
(option) is not used. Be sure to ground the MM-123A before use.
Toroidal coil/voltage detecting connector
When using the voltage measurement function, connect the toroidal coil
(MB-400M/MB-800M) and the voltage detection cable using the relay cable
(option).
Power supply switch
Turns on/off the power supply when the single-phase AC power supply
(100–240
V) is used.
Fuse holder
Has a fuse inside.
Fuse rating 250 V, 1 A, φ5 x 20 mm (Time delay, High interrupting
capacity)

MM-123A
5. Interface
5-1
5. Interface
(1) Connection Diagram of the External I/O Signals
Description of each pin on the external I/O connector.
Input signal is explained as contact input.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
SCH1
SCH2
SCH4
SCH8
SCH16
GATE
COUNT RST
NG RESET
NO CURR
SIG COM
TRG SIG
VOLT SIG
CURR SIG
SIG COM
COM
COM
NO CURR AC/DC24V
COM
INT.24V
EXT.COM
+

MM-123A
5. Interface
5-2
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
NG-L
NG-H
NG COM
GOOD
NO CURR
READY
COUNT UP
INT.24V
COM
NG+24V(+)
+
NG+24V(-)

MM-123A
5. Interface
5-3
(2) Description of the External I/O Signals
Pin No. Name Function
1, 26,
27, 28 INT.24V
Pins 1, 26, 27, and 28 are pins for the INT.24V. Pin 2 is the EXT.COM.
Connect pins as follows:
When using contacts or NPN transistors (sink type) on a PLC as input
signals to the I/O connector, connect either of INT.24V terminals and
Pin 2.
When using PNP transistors (source type) on a PLC as input signals to
the I/O connector, connect Pin 2 to the COM terminal of PLC.
The output capacity of the internal power supply is 24 V DC, 100
mA
max.
For details, see [5. (3) Connection of Input Signals].
When the MM-123A is operated with 24 V DC, connect INT.24V
terminal and all COM terminals (Pins 11, 16, 17, 30, 31, 32, and 33) as
shown below.
1
11
INT.24V
or Pins 26, 27, 28
and all of Pins 16, 17,
30, 31, 32
+24V
0V
24V DC
power supply
* When the MM-123A is operated with 24 V DC, do not connect the
power cable to the power cable connector. Connecting 24 V DC and
100 V power supply simultaneously may lead to malfunction.
2 EXT.COM
3
3: SCH1
4: SCH2
5: SCH4
6: SCH8
7: SCH16
Input pins for selecting the schedule number.
Select the schedule number by combing the pin numbers whose circuits
are closed among Pins 3 to 7. See table on the next page.
The schedule number selected by the I/O connector has priority over
that set by the Weld Checker. When selecting the schedule number by
the operation button on the Weld Checker, open the circuits of the Pins
3, 4, 5, 6 and 7.
Input the Schedule select [SCH] signal at least “input stabilizing time + 2
ms” before the welding current flows. The schedule number cannot be
changed during measurement.
For details of the input stabilizing time, see [7. (5) h. System Setting
(7) Input stabilizing time].
4
5
6
7
Welding current
[SCH] signal
t≧Input stabilizing time + 2ms

MM-123A
5. Interface
5-4
<Example combination of the SCH number and the SCH pin number>
Pin No.
SCH No. 7 6 5 4 3
Pin No.
SCH No. 7 6 5 4 3
1 ●17 ●●
2 ●18 ●●
3 ●●19 ●●●
4 ●20 ●●
5 ●●21 ●●●
6 ●●22 ●●●
7 ●●●23 ●●●●
8 ●24 ●●
9 ●●25 ●●●
10 ●●26 ●●●
11 ●●●27 ●●●●
12 ●●28 ●●●
13 ●●●29 ●●●●
14 ●●●30 ●●●●
15 ●●●●31 ●●●●●
16 ●
* When all pins are opened, the schedule number set by the main unit is selected.