NSD VARILIMIT VS-12PB User manual

NSP-Z0006-4
Electronic limit Switch
VS-12PB
SPECIFICATIONS
&
OPERATION MANUAL


6. Operation
- Do not change the controller's function switch settings during the
operation; otherwise, it will cause injury.
- Do not approach the machine after instantaneous power failure
has been recovered.
Doing so may result in injury if the machine starts abruptly, it will
cause injury.
- Be sure to check that the power supply specifications are correct;
otherwise, it may caused controller failure.
- Be sure to provide an external emergency stop circuit so that
operation can be stopped with power supply terminated immediately.
- Be sure to conduct independent trial runs for the controller before
mounting the controller to the machine;
otherwise, it may cause injury.
- When an error occur, be sure to eliminate the cause, ensure
safety, and reset the error before restarting operation;
otherwise, it may cause injury.
7. Maintenance And Inspection
- Do not disassemble, remodel, or repair the unit;
otherwise, it will cause electric shock, fire, and unit malfunction.
- The capacitor of the power line deteriorates through prolonged use.
We recommended that the capacitor be replaced every five years
to prevent secondary damage.
8. Disposal
- Be sure to handle the controller as industrial waste while
disposing of it.
1. Handling Precautions
- Do not touch components inside of the controller;
otherwise, it will cause electric shock.
- Do not damage the cable by applying excessive load, placing
heavy objects on it, or clamping;
otherwise, it will cause electric shock or fire.
DANGER
- Turn the power supply OFF before wiring, transporting, and inspecting
the controller; otherwise, it may cause electric shock.
- Provide an external safety circuit so that the entire system
functions safely even when the controller is faulty.
- Connect the grounding terminal of the controller;
otherwise, it may case electric shock or malfunction.
- Do not use the controller in the following places; water splashes,
the atmosphere of the corrosion, the atmosphere of the flammable
vapor, and the side of the combustibility.
Doing so may result in fire or the controller may become faulty.
- Be sure to use the controller and the ABSOCODER sensor in the
environment designated by the general specifications in the manual.
Failure to do so may result in electric shock, fire, malfunction or unit
failure.
- Be sure to use the specified combination of the ABSOCODER
sensor, controller and sensor cable; otherwise, it may cause fire or
controller malfunction.
CAUTION
2. Storage
CAUTION
- Do not store the controller in a place exposed to water, or toxic
gas and liquid.
- Be sure to store the controller in designed temperature and humidity
range, and do not exposed to direct sunlight.
- Be sure to consult with NSD when the controller is stored for long
periods.
- Do not hold the cable or shaft of ABSOCODER sensor during
transport; otherwise, it will cause injury or controller malfunction.
CAUTION
3. Transport
Thank you very much for purchasing our product.
Before operating this product, be sure to carefully read this manual so that
you may fully understand the product, safety instructions and precautions.
- Please submit this manual to the operators actually involved in operation.
- Please keep this manual in a handy place.
Symbol Meaning
DANGER
Incorrect handling may cause a hazardous situation that
will result in moderate injury or physical damage.
Incorrect handling may cause a hazardous situation that
will result in death or serious injury.
Instructions accompanied by a symbol may also result in serious
damage or injury. Be sure to follow the all instructions accompanied by the symbol.
Graphic Symbols
Symbol Meaning
Indicates prohibited items.
Indicates items that must be performed to.
This product is not designed to be used under any situation affecting human
life. When you are considering to use this product for special purposes such as
medical equipment, aerospace equipment, nuclear power control systems,
traffic systems, and etc., please consult with NSD.
This product is designed to be used under the industrial environments categorized
in Class A device.
The supplier and user may be required to take appropriate measures.
CAUTION
CAUTION
Application Limitation
4. Installation
- Do not step on the ABSOCODER sensor or place heavy objects on
the controller; otherwise, it will cause injury.
- Do not block the exhaust port or allow any foreign matter to enter
the controller; otherwise, it will cause fire or unit failure.
- Be sure to secure the controller and ABSOCODER sensor with the
provided brackets; otherwise, it may cause malfunction, injury, or
drop.
- Be sure to secure the specified distance between the main body
and the control panel or other equipments; otherwise, it may cause
malfunction.
5. Wiring
- Be sure to secure the terminal block firmly; otherwise, it may have
risk of fire.
- Be sure to mount the terminal cover provided with the controller,
before supplying the power, starting operation after the installation,
and wiring; otherwise, it may cause electric shock.
- Be sure to keep the sensor cable, control cable, and communication
cable at least 300 mm away from the main circuit and power line;
otherwise it may cause injury or malfunction.
- Be sure to connect all cables correctly; otherwise, it may cause injury
or controller malfunction.
- Be sure to firmly connect the external I/O connectors and sensor
connectors; otherwise, it may cause incorrect inputs and outputs or
injury.
CAUTION
CAUTION
(Please read this safety guide carefully before operation)
GENERAL SAFETY RULES
DANGER
CAUTION
CAUTION
CAUTION
Signal Words
Safety precautions in this guide are classified into DANGER and CAUTION.

REVISION HISTORY
The Document No. appears at the upper right of this manual's cover page.
Document No. Date Revision Description
NSP-Z0006-2
27, May, 2016
2nd Edition
Japanese document: NSP-99024-3
NSP-Z0006-3 12, Jul., 2019 3rd Edition
Japanese document: NSP-99024-4
NSP-Z0006-4
18, Oct., 2021
4th Edition
Japanese document: NSP-99024-5

CONTENTS
INTRODUCTORY SECTION
1
1-1
2
2-1
3
3-1
3-1-1
3-1-2
3-1-3
3-1-4
3-1-5
3-1-6
3-1-7
3-1-8
3-1-9
3-2
3-2-1
3-3
3-4
3-5
3-6
Page
1-1
1-1
2-1
2-1
3-1
3-1
3-1
3-1
3-2
3-2
3-3
3-4
3-5
3-6
3-6
3-7
3-7
3-8
3-8
3-9
3-9
General
Features
System Configuration
System Configuration
Functions
Position Setting Function
Automatic Positioning Function (AUTO)
Unidirectional Positioning
Speed-Switching Format
Speed-Stepping Format
Starting Operation From Inside STOP Zone
Timer Settings
Learning Function
INCH Function (INCH)
JOG Function (JOG)
Limit Switch Output Function
Protected Switch Function
Current Position Preset Function
Machine Position Check Function
Communication Function
Self-Diagnosis Function
SPECIFICATIONS SECTION
4
4-1
4-1-1
4-1-2
4-1-3
4-2
4-2-1
4-2-2
4-2-3
4-3
5
5-1
5-2
5-2-1
5-2-2
5-2-3
5-3
6
6-1
Page
4-1
4-1
4-1
4-1
4-2
4-3
4-3
4-3
4-4
4-4
5-1
5-1
5-2
5-2
5-4
5-5
5-7
6-1
6-1
Specifications
VS-12PB Specifications
General Specifications
Performance Specifications
Input/Output Signal Specifications
ABSOCODER Sensor Specifications
Multi-turn Type MRE Sensor (2-phase)
Multi-turn Type MRE Sensor (3-phase)
Linear Type VLS Sensor
Sensor Cable
Outer Dimensions
VS-12PB Controller
ABSOCODER Sensors
Multi-turn Type MRE Sensor (2-phase)
Multi-turn Type MRE Sensor (3-phase)
Linear Type VLS Sensor
Cable
Ordering Information
Configuration & Combinations

INSTALLATION & WIRING SECTION
7
7-1
7-2
7-2-1
7-2-2
8
8-1
8-1-1
8-1-2
8-1-3
8-1-4
8-2
Page
7-1
7-1
7-2
7-2
7-3
8-1
8-1
8-2
8-3
8-7
8-9
8-10
Installation
Verifying The Shipping Container Contents
Installation Condition & Precautions
Controller Installation
ABSOCODER Sensor Installation
Wiring
Terminal Board & Connector Connection
Power Supply Connection
Control I/O Signals
BCD Input/Output Connections
Communication Connector (RS-232C, RS-422)
Sensor Cable Connection
OPERATION SECTION
9
9-1
9-1-1
9-1-2
9-2
9-3
9-3-1
9-3-2
9-3-2-1
9-3-2-2
9-3-2-3
9-3-2-4
9-3-2-5
9-3-2-6
9-3-3
9-4
9-4-1
9-4-2
9-4-3
9-5
9-5-1
9-5-2
9-6
9-6-1
9-6-2
9-6-3
9-6-4
9-6-5
9-6-6
9-6-7
9-7
9-7-1
9-7-2
Page
9-1
9-1
9-1
9-4
9-5
9-5
9-5
9-6
9-7
9-8
9-8
9-9
9-10
9-11
9-12
9-13
9-13
9-14
9-15
9-17
9-18
9-21
9-22
9-22
9-25
9-26
9-27
9-27
9-28
9-29
9-30
9-30
9-31
Operation
Before Beginning Operation
Control Panel Nomenclature
Operation Sequence
Power ON
Designating The Initial Settings
Basic Initial Settings
Initial Settings
Sensor rotation (travel) direction settings
Decimal point setting (Initial No.91)
Sensor selection (Initial No.92)
Scale length setting (Initial No.93)
Minimum current position value (Initial No.94)
Current position value setting (Initial No.95)
Other Initial Settings
Parameter Settings
Setting Items for Dual Speed Positioning
Basic Parameter Setting Procedure
Other Parameter Settings
RUN
AUTO Positioning
JOG Operation
Limit Switch Output Settings
Limit Switch Settings
Protected Switch Function
Dog Output Delete
Dog Output Insert
Channel Delete
Program Batch Delete
Program Batch Copy
Other Operations
Use of Password to Protect Data
All Data Delete (Initialize)

MAINTENANCE SECTION
10
10-1
10-2
APPENDIX
APPENDIX 1.
APPENDIX 2.
APPENDIX 3.
Page
10-1
10-1
10-3
APPX-1
APPX-1
APPX-3
APPX-6
Troubleshooting
Error Display & Countermeasures
Error Reset Procedure
Initial Setting Data Sheet
Parameter Setting Data Sheet
Limit Switch Output Setting Data Sheet


INTRODUCTORY
SECTION
1. General
2. System Configutation
3. Functions

●1-1 ●
1. General
The VARILIMIT VS-12PB is a positioning Controller unit which is used together with NSD’s unique ABSOCODER
sensor to achieve high-precision positioning control.
Applications: Transport systems, press machines, assemble equipment, and packaging equipment, etc.
1-1. Features
Some of the main VS-12PB features are described below.
(1) Absolute Position Detection
Rotational or linear positions are monitored by absolute position detection format. Even when a power outage,
etc., occurs, the correct address of the ABSOCODER sensor’s current position will be instantly detected when
power is restored.
(2) Limit Switch Function
Limit switch outputs are possible at up to 8 points as positioning is executed toward the target position.
(3) Learning Function Enable Highly Accurate Positioning
When a discrepancy exists between the target position and the actual STOP position after a positioning
operation, the Learning function will automatically make the necessary calculations to eliminate this discrepancy
at the next positioning operation.
Furthermore, if a positioning operation ends without entering the “In-Position” zone, the positioning operation will
automatically be executed again.
(4) Self-Diagnosis Function
This function detects severed / disconnected sensor cables, checks the control outputs, and monitors the
braking count.
(5) Communication With Host Controller
Setting data can be down-loaded from and up-loaded to a Host Controller. Moreover, up to 32 VS-12PB units
can be controlled by a single Host Controller.
(6) Fine Positioning (Inching Function)
Extremely fine, slow-speed positioning control is enables by short-period On/OFF switching of the positioning
signals.
(7) Unidirectinal Positioning Function
Unidirectional positioning minimizes positioning errors caused by backlash.

●2-1 ●
2. System Configuration
2-1. System configuration
This basic VS-12PB system configuration is shown below.
●Basic System Configuration
NSD components are indicated by NSD mark. All other components must be supplied by the user.
Note
When the VS-T12 or VS-T12B setting display unit is used, settings cannot be specified by communications with a
personal computer or programmable controller because the VS-T12 or VS-T12B uses the controller’s communication
port.

●3-1 ●
3. Functions
3-1. Position Setting Function
3-1-1. Automatic Positioning Function (AUTO)
The ABSOCODER sensor detects the machine’s current position, and this position is compared with the target
position. The motor control signals are then output according to this comparison.
●Example of Automatic Positioning Control
3-1-2. Unidirectional Positioning
A unidirectional format is used for VS-12PB positioning in order to minimize positioning errors caused by
gear backlash, etc.
To execute positioning from the opposite direction, the target stop position must be overshot first, with
positioning then occurring from the prescribed direction after making a U-turn.
The VS-12PB automatically determines if a position overshoot is necessary, based on whether the current
position value is larger or smaller than the target stop position value, and on the parameter-designated
positioning direction (parameter No.42 : FWD or RVS). Direction designated by the parameter setting.
Note:
The overshoot amount is designated by a parameter setting.
If designated as “0”, bidirectional positioning (no overshooting) will occur.

●3-2 ●
3-1-3. Speed-Switching Format
With the Speed-Switching format, the speed switching signals (high-speed and low-speed) operate independently,
with the high-speed signal being ON during high-speed operation, and low-speed signal being ON during lowspeed
operation.
●Control Timing (For U-Turn Positioning)
3-1-4. Speed-Stepping Format
With the Speed-stepping format, the high-speed, medium-speed, and low-speed signals do not operate
independently.
Instead, they are combined to produce a stepped speed switching output.
●Control Timing (For U-Turn Positioning)

●3-3 ●
3-1-5. Starting Operation From Inside STOP Zone
When the STOP zone is entered, the motor control signals for the positioning operation are switched OFF, and
the brake is applied. With the VS-12PB unit, it is possible to start operation from inside the STOP zone if so
designated at parameter No.48.
The procedure for starting operation from inside the STOP zone is as shown below.
①Move the current position in the opposite direction from the parameter-designated positioning direction, by the
amount of the [ stop zone] + [START travel amount].
②Stop movement at that position.
③Execute the positioning operation again for the target stop position in question.
Note
1. For bidirectional positioning, a directional determination (FORWARD or REVERSE) is required at step ①
above, depending on the current position when the START occurs.
2. Operation will occur as shown below if the parameter No.48 setting is designated as “0” (Start From STOP
Zone Disabled).

●3-4 ●
3-1-6. Timer Settings
(Motion Non-Detection Timer & Motion Misdirection Non-Detection Timer)
The “motion non-detection timer” setting designates the period from the point when positioning begins, until the
point when the motion error function begins. Motion errors are determined by a monitoring function which
checks the amount of change in the current position value every 0.5 s.
The “motion misdirection non-detection timer” setting designates the period from the point when positioning
begins, until the point when the motion direction error detection function begins. Motion direction errors occur
when motion direction is opposite from the command direction. The motion direction is checked every 0.5 s.
The operation timing for these timers is as shown below.
The timer periods are designated by parameter settings.

●3-5 ●
3-1-7. Learning Function
When positioning is completed, the Learning function checks the discrepancy between the target stop position
and the actual stop position. It then automatically adjusts the STOP zone for the next operation based on the
discrepancy.
Depending on the positioning direction, either the FORWARD or REVERSE stop zone will be adjusted.
(The STOP zone is not corrected for “START from STOP zone” positioning operations.)
Stop zone corrections are performed when the “positioning completed” signal output occurs (“positioning” signal is off).
Machines with large inertias can be accommodated by changing the “positioning completed” detection timer
(parameter No.51).
If the stop position following a positioning operation is not within the In-Position zone, positioning will be repeated
maximum two times (RETRY operation) based on the STOP zone adjustment made by the Leaning function.
Note
The Learning function is not always effective for all positioning applications.

●3-6 ●
3-1-8. INCH Function (INCH)
The INCH function compensates for positional deviations caused by machine friction, etc., by adding the preset
INCH zone amount (parameter setting no.52) to the target position so that extremely low-speed positioning occurs.
When executing positioning operations for press dies, this function permits corrections for minute deviations caused
by machine wear and deformation, etc.
3-1-9. JOG Function
The JOG function permits positioning to be executed by external inputs, communication, or by key inputs at the
control panel without regard to the target stop position.

●3-7 ●
3-2. Limit Switch Output Function
With this function, the machine’s travel amount is detected by the ABSOCODER sensor, and external ON/OFF
signal outputs are used in place of conventional limit switches.
●Limit Switch Output Example
With the VS-12PB, up to 10 ON / OFF outputs per channel are possible.
3-2-1. Protected Switch Function
This function prevents limit switch output ON/OFF settings from being changed by the usual method. The
protected switch settings can be changed in the same manner as regular switches if “0” is specified at the
“number of protected switches” parameter setting item.

●3-8 ●
3-3. Current Position Preset Function
When this function is executed (by external input), the machine’s current position will be moved (corrected) to the
“PRE” position which has been pre-designated. The PRE function is enabled by “PRE input 1.2”.
●Application Example
The VS-12PB automatically identifies the travel direction by comparing the current position values every 100ms.
Once a “PRE” input is executed, any other “PRE” inputs within a period of 100ms will be ignored.
When a current position preset input is changed (both ON and OFF changes), subsequent preset inputs are
ignored for a period of 100ms. The CCW speeds are as shown below. Speeds of less than the shown values will
be interpreted as CW operations.
MRE
VLS
32SP
32SS 0.44 (r / min) 256PWB 0.12 mm/s
G64SP G64SS 0.88 (r / min)
512PWB 0.23 mm/s
G128SP
G128SS 1.76 (r / min)
G160SP
G160SS
2.20 (r / min)
1024PW 0.47 mm/s
G256SP G256SS 3.52 (r / min)
512PYB 0.12 mm/s
G320SP
G320SS
4.40 (r / min)
G640SS
8.80
(r / min) 1024PYB 0.23 mm/s
G1280SS 17.60 (r /min)
2048PY 0.47 mm/s
G2560SS 35.20 (r / min)
3-4. Machine Position Check Function
This function checks for deviations between the actual machine position and the current position indicated by the
controller.
If “Machine position confirmation:2” is specified at the “current position preset function selection” parameter setting,
the current position is compared with the current position preset 2 value during a FORWARD or REVERSE
operation, but the current position value is not corrected in accordance with preset input 2.
Although the current position preset function actually changes the controller’s current position value, this machine
position confirmation function does not. It simply activates a self-diagnosis ( “excessive correction amount change”
detection function). Even if the machine position confirmation function is selected, the current position preset
function operates in accordance with preset input 1.

●3-9 ●
3-5. Communication Function
The VS-12PB permits target positions and parameter settings to be specified from a programmable controller or
a personal computer by using this communication function. For details, please contact your NSD sales
representative. Moreover , as shown in the illustration below, up to 32 VS-12PB units can be controlled from a
single host programmable controller.
3-6. Self-Diagnosis Function
(1) Travel Detection and Travel Direction Error Detection Functions
Changes in the current position detected (every 0.5s) by the ABSOCODER sensor are checked to verify that
travel is occurring in accordance with the controller commands.
The interval between a positioning start and the point when error detection begins is determined by parameter
settings ( “no travel” detection timer, and “travel direction error” detection timer).
(2) STOP zone Upper / Lower Limit Over Detection Function
In cases where the STOP zone has been adjusted by the Learning function, this function checks the adjustment
amount to determine if it exceeds the pre-designated upper or lower STOP zone limit.
(3) Excessive Current Position Change Detection Function
The amount of current position change is checked every 20ms. This function detects cases where the amount
of change exceeds the “permissible current position change amount” designated by parameter No.65.
(4) Excessive Correction Amount Detection Function
This function detects cases where the amount of current position correction executed by the “current position
preset” function exceeds the “permissible correction amount” designated by parameter No.66.
(5) Upper Limit Violation detection Function
This function detects cases where the current position value exceeds the upper limit setting designated by
parameter No.61.
(6) Lower Limit Violation Detection Function
This function detects cases where the current position value is below the lower limit setting designated by
parameter No.62.
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