GSK 988T User Manual

In this user manual we have tried to describe the matters
concerning the operation of this CNC system to the greatest extent.
However, it is impossible to give particular descriptions for all
unnecessary or unallowable operations due to length limitation and

products application conditions；Therefore, the items not presented

herein should be regarded as “impossible” or “unallowable”.

Copyright is reserved to GSK CNC Equipment Co., Ltd. It
is illegal for any organization or individual to publish or reprint this
manual. GSK CNC Equipment Co., Ltd. reserves the right to ascertain
their legal liability.

GSK988T Turning CNC System User Manua(Volume Ⅱ)

Preface

Your Excellency,

We are honored by your purchase of this GSK 988 Turning CNC

System made by GSK CNC Equipment Co., Ltd.

This book is User Manual Volume II –“Installation and Debugging”.

To ensure safe and effective running, please read this manual carefully

before installation and operation.

Warning

Accident may occur by improper connection and operation！This

system can only be operated by authorized and qualified personnel.

Special caution:

The power supply fixed on/in the cabinet is exclusively used for the

CNC system made by GSK.

It can't be applied to other purposes, or else it may cause serious

danger!

II

Cautions

■ Delivery and storage

● Packing box over 6 layers in pile is unallowed.

● Never climb the packing box, stand on it or place heavy objects on it.

● Do not move or drag the products by the cables connected to it.

● Forbid collision or scratch to the panel and display screen.

● Avoid dampness, insolation and drenching.

■

Open-package inspection

● Confirm that the products are the required ones.

● Check whether the products are damaged in transit.

● Confirm that the parts in packing box are in accordance with the packing list.

Precautions

● Contact us in time if any inconsistence, shortage or damage is found.

■ Connection

● Only qualified personnel can connect the system or check the connection.

● The system must be earthed, and the earth resistance must be less than 0.1Ω.

The earth wire cannot be replaced by zero wire.

● The connection must be correct and firm to avoid any fault or unexpected
consequence.

● Connect with surge diode in the specified direction to avoid damage to the
system.

● Switch off power supply before plugging out or opening electric cabinet.

■ Troubleshooting

● Switch off power supply before troubleshooting or changing components.

● Check the fault when short circuit or overload occurs. Restart can only be done

after troubleshooting.

● Frequent switching on/off of the power is forbidden, and the interval time should
be at least 1 min.

III

GSK988T Turning CNC System User Manual (Volume Ⅱ)

ANNOUNCEMENT!

z This manual describes various possibilities as much as possible. However,

operations allowable or unallowable cannot be explained one by one due to

so many possibilities that may involve with, so the contents that are not

specially stated in this manual shall be regarded as unallowable.

WARNING！

z Please read this manual and a manual from machine tool builder carefully

before installation, programming and operation, and strictly observe the

requirements. Otherwise, products and machine may be damaged,

workpiece be scrapped or the user be injured.

CAUTION！

z Functions, technical indexes (such as precision and speed) described in

this user manual are only for this system. Actual function configuration and

technical performance of a machine tool with this CNC system are

determined by machine tool builder’s design, so functions and technical

indexes are subject to the user manual from machine tool builder.

z Though this system adopts standard operation panel, the functions of the

keys on the panel are defined by PLC program (ladder diagram). It should be

noted that the keys functions described herein are for the standard PLC

program (ladder diagram).

z For functions and effects of keys on control panel , please refer to the user

manual from machine tool builder.

This manual is subject to change without further notice.

IV

Precautions

Safety Responsibility

Manufacturer’s Responsibility

——Be responsible for the danger which should be eliminated and/or controlled on
design and configuration of the provided CNC systems and accessories.
——Be responsible for the safety of the provided CNC systems and accessories.
——Be responsible for the provided information and advice for the users.

User’s Responsibility

——Be trained with the safety operation of CNC system and familiar with the safety
operation procedures.
——Be responsible for the dangers caused by adding, changing or altering to the
original CNC systems and the accessories.

——Be responsible for the failure to observe the provisions for operation, adjustment,

maintenance, installation and storage in the manual.

This manual is reserved by end user.

We are full of heartfelt gratitude to you for supporting us in the

use of GSK’s products.

V

GSK988T Turning CNC System User Manual (Volume Ⅱ)

VI

Contents

Contents

CHAPTER I INSTALLATION LAYOUT ..............................................................................................1

1.1 Overall Dimension of GSK988T and Accessories...................................................................1

1.1.1 Overall Dimension of the GSK988T Mainframe............................................................1

1.1.2 Overall Dimension of GSK988T-H Mainframe..............................................................2

1.1.3 Overall Dimension of GSK988T Operation Panel MPU02A .........................................3

1.1.4 Overall Dimension of GSK988T Operation Panel MPU02B .........................................4

1.1.5 Overall Dimension of GSK988T- H Operation Panel MPU03A.....................................5

1.1.6 Overall Dimension of GSK988T-H Operation Panel MPU03B......................................6

1.1.7 Overall Dimension of I/O Deconcentrator MCT01 ........................................................7

1.1.8 Overall Dimension of I/O Deconcentrator MCT02 ........................................................7

1.2 Structure of GSK988T Control System ...................................................................................8

1.2.1 Front /Rear Panel Illustrations......................................................................................8

1.2.2 General Connection Diagram .....................................................................................10

1.3 GSK988T Installation............................................................................................................11

1.3.1 Conditions of Electric Cabinet Installation ..................................................................11

1.3.2 System Grounding Requirements ..............................................................................11

1.3.3 Interference Prevention Methods ...............................................................................11

CHAPTER II INTERFACE SIGNAL DEFINITION AND CONNECTION.............................................13

2.1 Connection with Drive Unit ...................................................................................................13

2.1.1 Definition of the Drive Interface ..................................................................................13

2.1.2 Signal Instruction........................................................................................................13

2.1.3 Connection with the Drive Unit Interface ....................................................................16

2.2 Connection with the Spindle .................................................................................................18

th

2.2.1 The 5

Axis · Spindle Interface Definition ...................................................................18

2.2.2 Signal Instruction........................................................................................................19

2.2.3 Connection with the Servo Spindle Drive Unit ............................................................20

2.2.4 Connection with the Spindle Inverter Interface...........................................................21

2.3 Connection with the Spindle Encoder...................................................................................22

2.3.1 Interface Definition of the Spindle Encoder ................................................................22

2.3.2 Signal Instruction........................................................................................................22

2.3.3 Connection with the Spindle Encoder Interface..........................................................22

nd

2.4 Connection with the 2

2.4.1 Definition of the 2

Spindle............................................................................................23

nd

Spindle (Analog Spindle) Interface ..............................................23

2.4.2 Connection with the 2nd Spindle Inverter Interface .....................................................23

2.5 Connection with MPG...........................................................................................................24

2.5.1 Definition of MPG Interface ........................................................................................24

2.5.2 Signal Instruction........................................................................................................24

2.5.3 Connection with MPG Interface..................................................................................24

2.6 Connection with the Machine Panel .....................................................................................25

2.6.1 Communication Interface Definition............................................................................25

2.7 GSK988T General I/O Interface Definition ...........................................................................25

2.7.1 Definition of Input & Output Addresses.......................................................................25

2.7.2 Input Signal ................................................................................................................26

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

2.7.3 Output Signal .............................................................................................................27

2.8 Connection with the Power Supply....................................................................................... 28

2.8.1 Definition of Power Supply Interface ..........................................................................29

2.8.2 Connection between GSK988T and GSK-PB2 Power Supply Box ............................ 29

2.9 Connection with the External Equipment..............................................................................29

2.9.1 RS-232 Interface Definition ........................................................................................30

2.9.2 Definition of GSKLINK Bus Interface..........................................................................30

2.9.2 Network Interface Definition .......................................................................................31

2.9.3 USB Interface Definition.............................................................................................31

CHAPTER III MACHINE TOOL DEBUGGING-OPERATION ............................................................32

3.1 Parameter Setting ................................................................................................................32

3.1.1 System Parameters....................................................................................................32

3.1.2 Servo Parameters ......................................................................................................34

3.2 Instruction of PC Communication Software GSKComm-M...................................................37

3.2.1 Preparation for GSKComm-M .................................................................................... 37

3.2.2 File Download (PC→CNC).........................................................................................38

3.2.3 Upload File (CNC→PC) .............................................................................................39

3.3 Usage of U Disk ...................................................................................................................40

3.3.1 File Management Screen ...........................................................................................40

3.3.2 Program Screen .........................................................................................................41

3.3.3 PLC Screen................................................................................................................42

3.4 PLC Operation .....................................................................................................................43

3.4.1 PLC Execution and Stop ............................................................................................44

3.4.2 PLC Monitoring and Diagnosis...................................................................................45

3.4.3 PLC Data Viewing and Setting ...................................................................................48

3.4.4 PLC On-line Modification............................................................................................50

3.4.5 PLC Program Transmission ....................................................................................... 58

3.5 CNC Diagnosis.....................................................................................................................58

3.6 Servo Diagnosis ...................................................................................................................60

CHAPTER IV MACHINE DEBUGGING-FUNCTIONS.......................................................................62

4.1 Emergency Stop and Hardware Limit...................................................................................62

4.2 Basic Axis Parameters Setting .............................................................................................63

4.2.1 Axis Property ..............................................................................................................63

4.2.2 GSKLink Communication Setting of Axis and Servo ..................................................64

4.3 Servo Related Setting ..........................................................................................................65

4.3.1 CNC Servo Parameter Setting ...................................................................................65

4.4 Gear Ratio Adjustment .........................................................................................................66

4.4.1 Gear Ratio Calculation ...............................................................................................67

4.4.2 Gear Ratio Setting......................................................................................................67

4.5 Acceleration/Deceleration Characteristic Adjustment ...........................................................68

4.6 Reference Point and Software Limit .....................................................................................69

4.6.1 Reference Point of Absolute Encoder Setting ............................................................70

4.6.2 Reference Point Setting with Dog ..............................................................................71

4.6.3 Reference Point Setting without Dog .........................................................................72

4.6.4 Setting of Stored Stroke Check ..................................................................................73

VIII

Contents

4.7 Pitch Error Compensation ....................................................................................................75

4.8 Backlash Compensation.......................................................................................................78

4.9 Spindle Function Adjustment ................................................................................................80

4.9.1 Spindle Encoder .........................................................................................................80

4.9.2 Spindle Speed Analog Voltage Control .......................................................................81

4.9.3 Double-Spindle Control ..............................................................................................83

CHAPTER V PARAMETER INSTRUCTION ...................................................................................84

5.1 Parameters of System Setting..............................................................................................85

5.2 Parameters of the Interfaces of Input and Output.................................................................85

5.3 Parameters of Axis Control/Setting Unit ...............................................................................85

5.4 Parameters of the Coordinate System..................................................................................89

5.5 Parameters of the Stroke Detection......................................................................................91

5.6 Parameters of the Feedrate..................................................................................................94

5.7 Parameters of Control of Acceleration/Deceleration.............................................................98

5.8 Parameter of Servo and Backlash Compensation..............................................................100

5.9 Parameter of Input/Output ..................................................................................................104

5.10 Parameter of Display and Editing .....................................................................................106

5.11 Parameter of Programming ..............................................................................................109

5.12 Parameters of the Screw Pitch Error Compensation ........................................................ 111

5.13 Parameters of the Spindle Control....................................................................................113

5.14 Parameters of the Tool Compensation .............................................................................117

5.15 Parameters of the Canned Cycle .....................................................................................120

5.15.1 Parameters of the Drilling Canned Cycle ...............................................................121

5.15.2 Parameters of the Thread Cutting Cycle ................................................................121

5.15.3 Parameters of the Combined Canned Cycle ..........................................................121

5.16 Parameters of the Rigid Tapping ......................................................................................123

5.17 Parameters of the Polar Coordinates Interpolation...........................................................125

5.18 Parameters of the User Macro Program...........................................................................126

5.19 Parameters of the Skip Function ......................................................................................127

5.20 Parameters of the Graphic Display...................................................................................128

5.21 Parameter of Run Hour and Parts Count Display.............................................................128

5.22 Parameter of MPG Feed ..................................................................................................129

5.23 Parameter of PLC Axis Control.........................................................................................131

5.24 Parameters of the Basic Function.....................................................................................134

5.25 Parameters of GSKLink Communication Function ...........................................................135

CHAPTER VI STANDARD PLC FUNCTION CONFIGURATION.....................................................136

6.1 Standard Panel on the Machine Tool ..................................................................................136

6.2 Addresses X, Y Definition ...................................................................................................137

6.2.1 General I/O Interface on Machine Tool .....................................................................137

6.2.2 MPG Interface ..........................................................................................................141

6.2.3 Spindle Interface .....................................................................................................142

6.2.4 Standard Operation Panel........................................................................................143

6.3 Standard PLC Functions.....................................................................................................147

6.3.1 Cycle Start and Feed Hold........................................................................................147

6.3.2 Feed/Spindle Hold....................................................................................................148

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

6.3.3 Program Lock...........................................................................................................149

6.3.4 Feedrate Override ....................................................................................................149

6.3.5 Spindle Override.......................................................................................................149

6.3.6 Spindle CCW/CW Control ........................................................................................ 150

6.3.7 Spindle Jog...............................................................................................................151

6.3.8 Spindle 8-Point Pre-Orientation................................................................................152

6.3.9 Spindle Speed Binary Control...................................................................................154

6.3.10 Spindle Gear Control.............................................................................................. 154

6.3.11 Cooling Control....................................................................................................... 155

6.3.12 Lubricating Control .................................................................................................156

6.3.13 Chuck Control ........................................................................................................157

6.3.14 Tailstock Control .....................................................................................................158

6.3.15 Low Pressure Detection .........................................................................................159

6.3.16 Overtravel Signal of Axes....................................................................................... 160

6.3.17 Tool Change Control...............................................................................................160

6.3.18 Emergency Stop.....................................................................................................165

6.3.19 Tri-Colored Lamp ...................................................................................................166

6.4 Standard PLC Parameter Instruction..................................................................................166

6.4.1 Parameter K ............................................................................................................. 166

6.4.2 Parameter DT...........................................................................................................167

6.4.3 Parameter DC .......................................................................................................... 168

6.4.4 Parameter D.............................................................................................................169

6.5 Signals G, F Used in Standard PLC....................................................................................169

6.5.1 Signal G ...................................................................................................................169

6.5.2 Signal F....................................................................................................................171

APPENDIX A ALARM LIST ..........................................................................................................173

A.1 Program Alarms (P/S Alarms)............................................................................................173

A.2 Parameter Alarms ..............................................................................................................183

A.3 Pulse Encoder Alarms........................................................................................................184

A.4 Servo Alarms .....................................................................................................................184

A.5 Overtravel Alarms ..............................................................................................................185

A.6 Spindle Alarms...................................................................................................................185

A.7 System Alarms...................................................................................................................185

A.8 PLC Alarms........................................................................................................................186

A.9 GSKLink Communication Prompts.....................................................................................188

A.10 Servo Inner Alarms ..........................................................................................................189

APPENDIX B MOTOR TYPE CODE LIST....................................................................................193

B.1 DAT2000C Series Motor Model Code List .........................................................................193

B.2 DAP03C,DAY3025C Model Code List ...............................................................................194

APPENDIX C COMMON ALARM REMEDY ................................................................................. 195

C.1 CNC Common Alarm Remedy........................................................................................... 195

C.2 DAT Feed Servo Alarm Remedy........................................................................................ 195

C.3 Spindle Servo Alarm Remedy ............................................................................................201

X

Chapter I Installation Layout

CHAPTER I INSTALLATION LAYOUT

1.1 Overall Dimension of GSK988T and Accessories

1.1.1 Overall Dimension of the GSK988T Mainframe

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

1.1.2 Overall Dimension of GSK988T-H Mainframe

Note: The panel of GSK988T-H is horizontal.

2

Chapter I Installation Layout

1.1.3 Overall Dimension of GSK988T Operation Panel MPU02A

0

9

0

1

0
2

0
3

0

0

8
0

7
0

6

0

4

50

30

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

1.1.4 Overall Dimension of GSK988T Operation Panel MPU02B

30

4

Chapter I Installation Layout

1.1.5 Overall Dimension of GSK988T- H Operation Panel MPU03A

30

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

1.1.6 Overall Dimension of GSK988T-H Operation Panel MPU03B

30

6

Chapter I Installation Layout

1.1.7 Overall Dimension of I/O Deconcentrator MCT01

1.1.8 Overall Dimension of I/O Deconcentrator MCT02

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

1.2 Structure of GSK988T Control System

1.2.1 Front /Rear Panel Illustrations

Connect to spindle encoder

ENCODER ENCODER 2

CN21

ST

1 AXIS

CN11

COM WITH
MACHINE PANEL

+24V

0V

-12V
0V

+12V

0V

+5V
+5V
+5V

CN1

MPG

GSKLINK(A)

CN53

CN31CN22

ND RD TH

CN12

3 AXIS 2 AXIS

4 AXIS

CN13 CN14

INPUT OUTPUT

CN54

CN61 CN62

GSKLINK(B)

CN52

ND

2 SPINDLE

CN41

TH

5 AXIS SPINDLE

CN15

Connect to spindle encoder 2

(It can be used as the 2nd MGP)

Used for communication between
CNC and remote I/O unit

Used for communication between
CNC and servo drive uni

Connect to MPG

Connect to the 2nd spindle

Feed axis interface (connect to

the 1～4 axes servo drive unit)

Output interface from CNC

to machine tool

Connect to spindle servo
drive unit/invertor/the 5th

axis servo drive unit

Input interface from
machine tool to CNC

Connect to machine tool panel

8

Power supply interface

Fig. 1-2-1 The layout of GSK988T mainframe rear cover interfaces

Note: These interfaces are compatible with GSK988T-H system. See Fig.1-2-1

Chapter I Installation Layout

ENCODER ENCODER 2

CN21

CN22

AXIS 2AXIS 1

MPG

CN31

AXIS 3

GSKLINK(A)

CN53

AXIS 4

CN14CN13CN11 CN12

GSKLINK(B)

CN52

SPINDLE 2

CN41

MACHINE PANEL

CN54

AXIS 5 SPINDLE

CN15

INPUT OUTPUT

+24V

0V

-12V
0V

+12V

0V

+5V
+5V
+5V

CN61CN62

CN1

Fig. 1-2-2 The layout of GSK988T-H mainframe rear cover interfaces

Fig. 1-2-3 The layout of GSK988T front panel interfaces

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

1.2.2 General Connection Diagram

GSK 988T

10

Fig. 1-2-4 GSK988T connection diagram

Chapter I Installation Layout

1.3 GSK988T Installation

1.3.1 Conditions of Electric Cabinet Installation

¾ Prevent the entry of dust, coolant and organic solution.

¾ The distance between CNC rear cover and the cabinet should not be less than 20cm.

Ensure that the temperature difference (outside and inside the cabinet) will be less than
10℃ in case of temperature rising in the cabinet.

¾ A radiator fan can be installed inside the cabinet to ensure ventilation.
¾ The display panel should be installed in proper place to avoid the coolant ejection.
¾ The interference of external electrical equipments to the CNC should be taken into

consideration and be reduced to the greatest extent.

1.3.2 System Grounding Requirements

The following grounding systems are for CNC machine tool:

¾ Signal ground

It provides the reference voltage of telecommunication system (0V).

¾ Frame ground

It is used for the sake of safety. The shell of frame unit, panel and the interface cables
shield should be connected together. It can also suppress the internal and external
noise.

¾ System ground

It is used to connect the devices and the frame ground with the ground.

Note 1: The connection between signal and frame ground in the CNC control unit is only made at one

place.

Note 2: Use the AC power line with grounding wire to ensure grounding during power supply.

1.3.3 Interference Prevention Methods

Measures such as shielding electromagnetic radiation, absorbing impulse current and
filtering power noise are taken into CNC design, which, to some extent, protects the CNC to
external interference. To ensure a steady working of CNC, it is necessary to take following
measures during CNC installation:

① Keep CNC far away from the interference source (such as inverter, AC contactor, static

generator, high pressure generator and sectioning for power line, etc.)

② The power to CNC should be supplied via insulation transformer; the machine installed

with CNC should be grounding; the CNC and drive unit should be connected with
independent grounding wire via grounding point.

③ Interference suppression: connect the RC circuits parallelly at two ends of the AC coil;

the RC circuit should be installed to the inductive load as near as possible; fly-wheel
diode should be inversely connected in serial at two ends of the DC coil ; surge absorber
should be connected in parallel at the winding head of AC motor (see Fig. 1-3-1).

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Fig. 1-3-1

④ The outgoing cable of CNC is twisted shielded cable or shielded cable; the shielding

layer of the cable is single-end earthed at CNC side; the signal line should be as short
as possible.

⑤ To reduce the interference between CNC signal cables and high-voltage cable, the

following principles should be followed when wiring:

Group Cable type Group Cable type

AC power line DC coil (24VDC)

A

C

Wiring Requirements:

¾ The cable should be twisted pair.
¾ Bundle the cables of group A separately from the cables in groups B, C, and the distance

should be no less than 10cm; or, make electromagnetic shielding for the cables in group A.

¾ Bundle the cables of group C separately from the cables in group A, and the distance should

be no less than 10cm; or, make electromagnetic shielding for the cables in group C; the
distance between group C cables and group B cables should be no less than 10cm.

¾ Bundle the cables of group B separately from the cables in group A; or, make

electromagnetic shielding for the cables in group B; cables in group B should be bundled
separately from the group C cables as far as possible.

Cables between CNC and servo

AC coil DC relay (24VDC)

Cables between CNC and high-voltage

AC contactor

drive unit

B

electric cabinet

Cables between CNC and machine tool

12

Chapter II Interface Signal Definition and Connection

CHAPTER Ⅱ INTERFACE SIGNAL DEFINITION AND

CONNECTION

2.1 Connection with Drive Unit

2.1.1 Definition of the Drive Interface

1：nCP+
2：nDIR+
3：nPC
4：+24V
5：nALM
6：nSET
7：nEN

Fig. 2-1-1 CN11, CN12, CN13 and
CN14 interfaces (15 pins, D-type

注：n 代表 1、2、3 或 4, 以下相同;

female)

Note: CN1 is the 1st servo axis interface, CN2 is the 2nd one, CN3 the 3rd one, and CN4 the 4th one. Each

controlled axis outputs the corresponding servo axis interface, which is set by parameter NO.1023.

9： nCP-
10：nDIR­11：0V
12：+5V
13：+5V
14：0V
15：0V

Signal Description

nCP+、nCP-

nDIR+、nDIR-

nPC Zero point signal

nALM Drive unit alarm signal

nEN Axial enable signal

nSET Pulse inhibition signal

nRDY Servo ready signal

Command pulse signal

Command direction signal

2.1.2 Signal Instruction

(1) Command pulse signal and nCP and command direction signal nDIR

nCP+ and nCP- are command pulse signals, nDIR+ and nDIR- are command direction
signals, the two groups of signals all are difference (AM26LS31) output, the external is suggested
to use AM26LS32 for receiving, refer to the following Fig.2-1-2 about the internal circuit:

Fig. 2-1-2 Internal circuit of nCP and nDIR

(2) Drive unit alarm signal nALM

The drive alarm level is low or high, which is set by 0 bit of parameter 1816; refer to Fig.2-1-3
for the internal circuit.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Fig. 2-1-3. Internal circuit of nALM

Input circuit of this type requires that the drive should provide the signal through the methods

in the following Fig. 2-1-4:

Method 1: Method 2:

Fig. 2-1-4. Methods of the drive unit providing signals

(3) Servo ready signal nRDY

nRDY signal is connected to the servo drive unit ready signal. See Fig. 2-1-5.

(4) Axial enable signal nEN

When CNC is running normally, nEN signal output is valid (nEN signal connects with 0V),
and the drive or the emergency stop alarms, CNC switched off, nEN signal outputs (nEn signal
cuts off 0V). About the internal interface circuit, refer to the following Fig. 2-1-6:

Fig. 2-1-5 Internal circuit of nRDY

Fig. 2-1-6. Internal circuit of nEN

(5) Pulse inhibition signal nSET

nSET signal indicates the servo input inhibition. To improve the anti-interference ability
between CNC and the drive, the signal is low-level when CNC outputs the pulse signal, if there

14

Chapter II Interface Signal Definition and Connection

isn’t any pulse signals, it is high level; refer to the following Fig. 2-1-7 about the internal interface
circuit:

Fig. 2-1-7 Pulse forbidden signal circuit

(6) Zero point signal nPC

Take one-rotation signal of motor encoder or proximity switch signal as zero signals. About

the internal connection circuit, refer to Fig. 2-1-8:

Fig. 2-1-8 Zero point signal circuit

① The illogram of PC signals provided by user is shown in Fig. 2-1-9:

Fig. 2-1-9 Signal illogram

Note: During machine zero return, after releasing the deceleration switch, CNC determines the position of

the reference point through detecting PC signal jumping, and the rising edge check and the falling
edge check are both valid.

② Refer to Fig. 2-1-10 for the connection method of taking one NPN-type Hall unit as the
deceleration signal:

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Fig. 2-1-10 Connection with NPN-type Hall unit

③ Refer to the following Fig. 2-1-11 about the connection method of taking one Hall unit in
PNP type as one deceleration signal:

Fig. 2-1-11 Connection with Hall unit in PNP type

2.1.3 Connection with the Drive Unit Interface

The connection between GSK988T system and GSK DA98B drive unit is shown in the
following figure.

16

Chapter II Interface Signal Definition and Connection

Fig. 2-1-12 Connection between GSK988T and DA98B

The connection between GSK988T and GSK DAT2000C drive unit is shown as follows:

Fig. 2-1-13 Connection between GSK988T and DAT2000C drive unit

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

2.2 Connection with the Spindle

The spindle interface of GSK988T is CN15 (the fifth axis · spindle interface). It is equipped
with the function of pulse output and analog voltage output, and can be adopted with the servo

th

spindle drive unit or the common spindle Inverter, or taken as an independent 5

servo axial
interface. Moreover, GSK988T system is also equipped with the 2nd spindle interface CN41 (refer
to following chapters for details), and it can output 0~+10V analog voltage for extending the 2

nd

spindle or the power unit.

2.2.1 The 5th Axis · Spindle Interface Definition

1：SCP+
2：SDIR+
3：GND
4：SALM
5：X5.0(VPO)
6：X5.1(SAR/PAR)
7：SRDY
8：X5.2(ZSP)
9：GND
10：SPC
11：+24V
12：AGND
13：SVC

Fig. 2-2-1 CN15 servo spindle interface (25 cords, D type female)

14：SCP­15：SDIR­16：GND
17：+24V
18：SSET
19：SEN
20：Y5.0(VP)
21：Y5.1(TAP)
22：Y5.2(SFR)
23：Y5.3(SRV)
24：GND
25：AGND

18

Chapter II Interface Signal Definition and Connection

Signal

Definition

SCP+, SCP-

SDIR+,SDIR-

SALM Drive unit alarm signal /

SRDY

SSET

SEN

SPC

SVC

AGND

X5.0 (VPO)

X5.1 (SAR/PAR)

X5.2 (ZSP)

Y5.0 (VP)

Y5.1 (TAP) Address of PLC signal, binary output

Y5.2 (SFR)

Y5.3 (SRV)

+24V

GND

Command pulse signal

Command direction signal

Servo ready signal

Pulse forbidden signal

Axial enable signal

Zero point signal

0~+10V analog voltage output

Analog voltage output ground

Address of PLC signal, binary input

Address of PLC signal, binary input

Address of PLC signal, binary input

Address of PLC signal, binary output

Address of PLC signal, binary output

Address of PLC signal, binary output

+24V

0V (binary input & output signal ground ) /

Explanation

Function Defined by Standard

Spindle speed/position status signal

Spindle position/speed reaching signal

Spindle output at zero speed signal

Spindle speed/position switch signal

Spindle speed loop gain selection
signal 2 (used for tapping)

PLC Address

/

/

/

/

/

/

/

/

Spindle CW signal

Spindle CCW signal

/

2.2.2 Signal Instruction

In the 5th axis • spindle interface, the internal circuits of SCP+, SCP-, SDIR+, SDIR-, SALM,
SRDY, SSET, SEN are consistent with that of the similar signal in the drive interfaces CN11,
CN12, CN13, CN14. Refer to section 2.1.2.

(1) Zero point signal SPC

SPC signal is valid at low level. It is different with the nPC signal in CN11, CN12, CN13,
CN14 interfaces (high-level nPC signal is valid). The internal circuit of SPC is shown in Fig. 2-2-2:

Fig. 2-2-2 Internal circuit of SPC
(2) Signals X5.0, X 5.1, X 5.2, X 5.3, X5.4
Signals X5.0, X 5.1, X 5.2, X 5.3, X 5.4 are the PLC signal addresses; binary input; the

internal circuit is shown in Fig.2-2-3.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Fig.2-2-3

Note: In the 5th axis • spindle interface, low-level signals X5.0, X5.1, X5.2, X5.3, X5.4 are valid. The X

address in general input CN61 (X0.0~X0.7, X1.0~X1.7, X2.0~X2.7, X3.0~X3.7) are valid during
high-level input.

(3) Signals Y5.0, Y 5.1, Y 5.2, Y 5.3, Y 5.4
Signals Y5.0, Y 5.1, Y 5.2, Y 5.3, Y 5.4 are the PLC signal addresses; binary output. The

internal circuit is shown in Fig. 2-2-4:

Fig. 2-2-4

2.2.3 Connection with the Servo Spindle Drive Unit

Connection between GSK988T and GSKDAP03C servo spindle drive unit is shown in the
following figure. This connection can also be applied in spindle servo drive unit such as GSK
DAP03/DAY3025C/DAY3025/DAY3100.

20

Chapter II Interface Signal Definition and Connection

Fig. 2-2-5 Connection between GSK988T and DAP03C drive unit

2.2.4 Connection with the Spindle Inverter Interface

The 5th axis ·spindle interface (CN15) SVC port outputs 0~+10V voltage, the connection

between GSK988T and the spindle inverter is shown in the following figure:

Fig. 2-2-6 Connection between GSK988T and inverter

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

2.3 Connection with the Spindle Encoder

GSK988T is equipped with two-channel encoder input interfaces (CN21 and CN22), CN21
interface is used as feedback input of spindle speed by default. When multi-spindle control
function is started, select the encoder interface which receives the feedback pulse for the system
control, through the selection signal PC2SLC (G28.7) of spindle encoder in PLC. When the
interface (CN22) of encoder 2 does not connect to the encoder and the selection signal PC2SLC
of the position encoder is not set to 1, CN21 interface is taken as the feedback input of the
spindle speed.

2.3.1 Interface Definition of the Spindle Encoder

8:PAS/HA1
7:*PAS
6:PBS/HB1
5:*PBS
4:PCS
3:*PCS
2:
1:

15：0V
14：0V
13：+5V
12：+5V
11：0V
10：
9：

Fig. 2-3-1 Encoder interface of CN21
and CN22 (15 pins, D-type, male)

Signal Description

*PAS/PAS Encoder phase A pulse

*PBS/PBS Encoder phase B pulse

*PCS/PCS Encoder phase C pulse

The 2

HA1 (Only CN22 is

with the signal)

HB1 (Only CN22 is

with the signal)

(When it’s not used in the 2

spindle encoder, it can be used

The 2

(When it’s not used in the 2

spindle encoder, it can be used

phase A signal

to extend the 2

nd

MPG phase B signal

to extend the 2

nd

MPG

nd

nd

MPG)

MPG.)

nd

nd

2.3.2 Signal Instruction

*PCS/PCS, *PBS/PBS and *PAS/PAS are difference input signals of phase C, B and A
respectively; *PAS/PAS and *PBS/PBS is the orthogonal square wave with difference of 90°, the
maximum signal frequency <1MHz: The quantity of GSK988T encoder pulses is set by parameter

nd

No.3773 (the quantity of the spindle encoder pulses) and No.3803 (the quantity of the 2

spindle

encoder).

2.3.3 Connection with the Spindle Encoder Interface

The connection between GSK988T and the spindle encoder with the twisted pair line is
shown in Fig. 2-3-2, and Changchun Yiguang ZLF-12-102.4BM-C05D encoder is taken as one
example:

22

Chapter II Interface Signal Definition and Connection

Changchun

GSK988T（CN21、CN22）

*PC

3

S

Yiguang 1024
encoder

8

ZZ

PCS

4

*PB

S

5

PBS

6
7
8

11

*PA

PAS
0
+5V

S

V

12

Metal cabinet

Fig. 2-3-2 Connection between GSK988T and the encoder

2
6
3
7
5
4

11

B
B

AA

0

V

+5V

2.4 Connection with the 2nd Spindle

988T supports multi-spindle function. Two spindle analog voltage output interfaces include

5th axis ·spindle (CN15) interface and the 2nd spindle (CN41) interface. They are controlled by

nd

PLC signals. The 2

spindle interface can be used to the 2nd inverter spindle or the unit head.

2.4.1 Definition of the 2nd Spindle (Analog Spindle) Interface

5：SVC
4：GND
3：Unused
2：Unused
1：Unused

CN41 analog spindle interface

(9pins, D-type, male)

1

Fig.2-4-1

6

9：Unused
8：Unused
7：Unused
6：Unused

Signal Description

SVC 0~+10V analog voltage output

GND analog voltage output ground

2.4.2 Connection with the 2nd Spindle Inverter Interface

The 2nd spindle interface SVC port outputs 0~10V voltage. The connection is shown in Fig.

2-4-2:

Fig. 2-4-2 Connection between GSK988T and the 2

nd

spindle inverter

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

2.5 Connection with MPG

2.5.1 Definition of MPG Interface

9: X6.3
8: X6.2
7: Unused
6: X6.1
5: X6.0
4: HB­3: HB+
2: HA­1: HA+

Fig. 2-5-1 CN31 MPG interface
(26 pins, D-type male)

18: +24V
17: +24V
16: +5V
15: +5V
14: +5V
13: 0V
12: 0V
11: 0V
10: 0V

26: X7.0
25: X6.7
24: X6.6
23: X6.5
22: X6.4
21: Unused
20: Unused
19: Unused

Signal Description

HA+, HA- MPG phase A signal input

HB+, HB- MPG phase B signal input

X6.0~X7.0

PLC signal address; binary

input

2.5.2 Signal Instruction

HA+, HA- and HB+, HB- are difference input signals of MPG phase A and B respectively.
X6.0~X7.0 interfaces are input addresses defined by PLC interface, and it can also be used for
axial selection of external MPG box and gear signal input.

Fig. 2-5-2 Inside circul of X6.0~X7.0 signal

2.5.3 Connection with MPG Interface

The typical connection between GSK988T and MPG is shown as the following figure:

24

Chapter II Interface Signal Definition and Connection

2.6 Connection with the Machine Panel

Connect between GSK988T system and the machine panel through communication.

2.6.1 Communication Interface Definition

Fig. 2-6-1 Standard machine panel interface CN54

(15 pins, D-type male)

Pin No. Signal IN/OUT Description

1 RXDA IN Receive data difference signal

2 RXDB IN Receive data difference signal

4 TXDA OUT Send data difference signal

5 TXDB OUT Send data difference signal

7 RESET OUT Panel resetting signal

2.7 GSK988T General I/O Interface Definition

2.7.1 Definition of Input & Output Addresses

Table 2-11 Definition of input & output addresses

Interface

CN61 (male)

input

CN61

Pin No.

1 X0.0 1 Y0.0

2 X0.1 2 Y0.1

3 X0.2 3 Y0.2

4 X0.3 4 Y0.3

5 X0.4 5 Y0.4

6 X0.5 6 Y0.5

7 X0.6 7 Y0.6

8 X0.7 8 Y0.7

9 X1.0 9 Y1.0

10 X1.1 10 Y1.1

11 X1.2 11 Y1. 2

12 X1.3 12 Y1.3

13 X1.4 13 Y1.4

14 X1.5 14 Y1.5

15 X1.6 15 Y1.6

16 X1.7 16 Y1.7

29

30

31

32

33

PLC

Address

X2.0

X2.1

X2.2

X2.3

X2.4

Interface

CN62 (female)

output

CN62

Pin No.

29

30

31

32

33

PLC

Address

Y2.0

Y2.1

Y2.2

Y2.3

Y2.4

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

34

35

36

37

38

39

40

41

42

43

44

17

18

19

20

25

26

X2.5

X2.6

X2.7

X3.0

X3.1

X3.2

X3.3

X3.4

X3.5

X3.6

X3.7

X4.0

X4.1

X4.2

X4.3

X4.4

X4.5

34

35

36

37

38

39

40

41

42

43

44

17~19, 26~28

20~25

Y2.5

Y2.6

Y2.7

Y3.0

Y3.1

Y3.2

Y3.3

Y3.4

Y3.5

Y3.6

Y3.7

0V

+24V

27

28

21~24

X4.6

X4.7

0V

2.7.2 Input Signal

Input signal is the one which the machine electric wire or the machine panel transmits to
CNC, and after connecting the input signal and +24V, the input is valid; if they are cut off, the
input is invalid. The input signal of contacts on the machine side should satisfy the following
conditions:

Contact capacity: DC30V, 16mA above;

Leakage current between contacts during opening: Below 1mA;

Voltage drop between contacts during closing: Below 2V (Current 8.5mA, including the cable
potential drop).

There are two methods of external input for input signals: one is switch input with contacts,
the connection is shown in Fig. 2-7-1:

26

Fig. 2-7-1

Chapter II Interface Signal Definition and Connection

The other is switch (transistor) input free of contacts; connection is shown in Fig. 2-7-2 and

Fig. 2-7-3.

Fig. 2-7-2 NPN type

Fig. 2-7-3 PNP type

2.7.3 Output Signal

Output signal is used for the drive machine electrical wire side or the relay and the indicator
on the machine panel side. When the output signal connects with 0V, the output function is valid
(Y output signal is 1); cut off 0V, the output function is invalid (Y output signal is 0). The circuit is
shown in the following Fig. 2-7-4:

Fig. 2-7-4. Internal circuit of the output signals

Therefore, the signal has two output statuses: OV output or high resistance. The typical
application is as below:

z Drive light diode

Use ULN2803 to output drive light diode and need the serial connection with one resistance,

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

limit the current from light diode (normally 10mA), which is shown in Fig. 2-7-5:

Fig. 2-7-5: Drive light diode

z Indicator in drive filament type

ULN2803 is used to output the indicator in drive filament type, and externally connect with
one preheated resistance to reduce the current shock during break-over, and the value of the
preheated resistance is based on that the indicator is off, which is shown in Fig. 2-7-6:

Fig. 2-7-6

z Drive inductive loading (such as the relay)

Output the drive inductive loading in ULN2803 type and it requires connecting the fly-wheel
diode close to the circuit, which is to protect the output circuit and reduce the interference, which
is shown in Fig. 2-7-7:

Fig. 2-7-7

2.8 Connection with the Power Supply

GSK988T uses GSK-PB2 power supply box, There are 4 groups of voltage: +5V (3A), +12V
(1A), -12V (0.5A) and +24V (0.5A), and common port COM (0V).

28

Chapter II Interface Signal Definition and Connection

2.8.1 Definition of Power Supply Interface

The interfaces of power supply are shown in Fig. 2-8-1 and 2-8-2:

+24V

0V

-12V
0V

+12V

0V

+5V
+5V
+5V

Fig. 2-8-1 power supply interface CN1 Fig. 2-8-2 power supply interface on the panel

2.8.2 Connection between GSK988T and GSK-PB2 Power Supply Box

When GSK988T is dispatched from the factory, GSK-PB2 power supply box and GSK988T
power supply interface has been already connected, so the user just need to connect to 220V AC
power supply. The connection between GSK-PB2 power supply box and GSK988T power supply
interface is shown in Fig. 2-8-3:

Fig. 2-8-3

2.9 Connection with the External Equipment

There are three interfaces on the left side of GSK988T LCD display screen: USB (flash
driver), internet and RS-232 interfaces, which are shown in the following figure. All the three
interfaces can be used for processing the file, two-way transmission between the system Para file
and PLC file and upgrading the system software. Among them, the internet interface can also be
used for remote monitor from PC to 988T system.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

USB interface

Internet interface

RS-232 interface

Fig. 2-9-1 GSK988T front panel interface

2.9.1 RS-232 Interface Definition

RS-232 communication interface:

1

5: GND
4:
3: TXD
2: RXD
1:

6

9:
8:
7:
6:

Fig. 2-9-2 RS-232 interface

(9 holes, D type female )

GSK988T executes communication through RS232 with PC (GSKComm-M communication

software should be installed). The connection is shown in Fig. 2-9-3:

Pin No. Signal

2 RXD

3 TXD

5 GND

Fig. 2-9-3 Connection between GSK988T and PC

2.9.2 Definition of GSKLINK Bus Interface

GSK988T is with GSKLink interfaces of two routes for connecting with the remote IO units
and the servo drive unit with GSKLink communication function. Among them, CN53 (GSKLINK
serial bus A) is for communication between CNC and the servo drive unit to realize real-time
monitor of servo parameter configuration and servo unit; CN52 (GSKLINK serial bus B) is for

30

Chapter II Interface Signal Definition and Connection

communication between CNC and remote IO unit.

1：GND
2：CANn_L
3：
4：GND

1

6

6：
7：CANn_
8：
9：

H

5：

Fig 2-9-4 GSKLink bus interface CN53 and
CN52 (9 holes, D type female)

2.9.2 Network Interface Definition

Network interface (standard):

Pin No. Signal Pin No. Signal

1 TXDLAN+ 9 LINK_LED

2 TXDLAN- 11 LAN_LED

3 RXDLAN+ 10, 12 VDD33

6 RXDLAN- 13, 14 Chassis ground

Signal Description

CANn_L

Low level of data

difference signal

CANn_H High level of data

difference signal

GND Signal ground

2.9.3 USB Interface Definition

Main USB interface (standard):

Pin No. Signal

1

2

3

4

5, 6

VCC(+5V)

USB_DN0

USB_DP0

GND

Chassis ground

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

CHAPTER III MACHINE TOOL DEBUGGING-OPERATION

3.1 Parameter Setting

The modification, backup and recovery of GSK988T system parameters and servo parameters
can only be done under such conditions: higher than 3rd management level; parameter switch is ON
and the system is in MDI mode. The operation of turning ON the parameter switch is shown as
follows:

Enter into System

Setting screen

1.Unlock the

program switch

2. Press SET key

3.Press CNC Setting

4.Press System Setting

5.Move the cursor

to “Parameter Switch”

6.Press to turn ON
the parameter switch

Note 1: After parameters are modified, the modification is valid to some parameters immediately;

some will be valid only after power on again. For details, please refer to chapter 5 Parameter
Instruction.

Note 2: To view or modify the servo parameters in CNC, please ensure the correctness of servo

system connection and servo slave configuration.

3.1.1 System Parameters

Press －> －> to enter into system parameter setting screen.

The system parameters can be set and modified on this screen. The current set parameters can

be backed up, and system default parameter or backup parameters can be recovered.

(1) Bit type parameters setting

Method 1:

① Select the parameter to be modified through keys

32

, , , ; or press

Chapter Machine Ⅲ Tool Debugging-operation

softkey and input the parameter number, then press softkey, the cursor

will move too the desired parameter.

② Press key

parameter in the figure below:

to make the selected parameter modifiable. For example, the No.0000

③ Press the numeric keys to input 8 binary values, and then, press

setting. (When the number input values is less than 8, fills the vacated bits with 0.)

④ Select other parameters through keys

Method 2:

①

Select the parameter to be modified through keys

Select the bits to be modified through keys

③ Press repeatedly, to switch the parameter bit between 0 and 1.
④ Move the cursor to complete the setting.

⑤ Select other parameters through keys , , , .

(2) Numeric type parameter setting

① Select the parameter to be modified through keys

softkey and input the parameter number, then press softkey, the cursor will

move to the desired parameter.

, , , .

, , , .

and .

to complete the

, , , ; or press

② Press key

to make the selected parameter modifiable.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

③ Input the numbers to be set through numeric keys, then press

④ Select other parameters through keys , , , .

(3) Parameters backup and recovery

Before modification, the parameters can be backed up through softkey. When the

modification is erroneous or the parameter does not need to be modified, press
backup parameters or system default parameters can be recovered.

¾ Parameter backup

① Press

②

Press

¾ Parameter recovery:

① Press

② Press

on the parameter screen, will be displayed.

to back up the current set parameters.

, will be displayed.

key to restore the backup parameters; Press to restore the

to complete the setting.

softkey, the

system default parameters; press to exit from the parameter screen.

3.1.2 Servo Parameters

(1) Modification and save

When the GSKLink communication is in normal state, on system screen, press

, to enter into servo parameter screen.

－>

34

Chapter Machine Ⅲ Tool Debugging-operation

Servo parameters can be viewed, modified, saved, backed up and restored through servo

parameter screen on the CNC side.

Axes switching: Press

parameters.

Parameter modification: Press key

parameter value directly, then press

Parameter saving: after the modification, press

parameter remains the same after servo is turned ON again.

Parameter backup: Press

to back up the file.

Parameter recovery: Press , the following dialogue box will pop up, the press

to restore the backup file.

, or to switch the displayed servo

and input the parameter value, or, input the

to complete the modification.

to save the parameter. The saved

, the following dialogue box will pop up, then press

Select effective parameter: if the parameters are modified on the servo, after power-on, the
system will issue prompt No.5030 “*the servo parameter in current parameter file of axis servo is
inconsistent with the read servo parameter.” Switch to the servo parameter screen this time, see Fig.

3-1-6 , then press

, see Fig. 3-1-7.

Fig.3-1-6

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Fig. 3-1-7

Press

read from the servo; press

(2) Restore motor default parameter

a. Refer to appendix B.1 to find the index value in the current software version of drive unit

b. Modify servo parameter PA1 to make it equal to the searched motor index value.
c. After modifying PA1, the system automatically update the default parameter

to validate the servo parameters in CNC; press to validate the parameters

to return to the screen shown in Fig. 3-1-6.

which is connected to the motor according to the motor type given on the motor
nameplate.

corresponding to the motor. The parameter value is valid immediately after modification.

36

Fig. 3-1-8

Chapter Machine Ⅲ Tool Debugging-operation

3.2 Instruction of PC Communication Software GSKComm-M

This section is a simple instruction for the usage of the GSKComm-M during machine

tool debugging. For the details, please refer to the GSKComm-M Instructions on the CD.

GSKComm-M is a communication management software especially provided for the machine
tool builders. The GSKComm-M screen is shown as follows. It can realize the following functions:
upload and download of files between PC and CNC, DNC communication, CNC parameter editing,
part program management and editing, viewing tool compensation data and screw pitch error
compensation data, ladder diagram editing, etc. It is convenient, efficient and reliable.

3.2.1 Preparation for GSKComm-M

(1) RS-232 series port connection

¾ Connection between PC and CNC

When both PC and CNC are power-off, the communication cable should be connected as

follows: DB9 male is plugged into the RS-232 communication interface on the CNC; DB9 female
is plugged into the 9 pins serial ports on the PC (COM0 or COM1).

¾ Baudrate setting in CNC
The baudrate is set by parameter No.0123. When data transmission is processed between

CNC and PC, the setting value should not be less than 4800. (ex-factory value:115200)

¾ Baudrate setting in PC

After the communication software is executed, left-click
the menu and select “Communication－>Communication Setup”,

shown in right figure.

Setting: select the serial port communication.
Port selection: select ports used for communication

(COM1, COM2, COM3, COM4)

Baudrate: Select the baudrate

(4800, 9600, 19200, 18400, 57600, 115200) (unit: bps)

(2) Network connection

¾ Connection between PC and CNC:
Connect the network port of GSK988T to the PC or router with normal network cable.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

¾ IP setting on CNC:

Press －> －> , to enter into IP setting page to set the IP address and

gateway.
¾ IP setting on PC:

After the communication software runs, left-click the menu,

and select “Communication－>Communication Setup”,

shown in right figure.
Communication setting: Select network communication.
Network setting: Fill in the IP set in CNC.

(3) Authority setting

During upload and download using GSKComm, corresponding authority should be set in

advance, otherwise, the operation will fail.

Data to be

downloaded

PLC files 2 level

parameters 3 level Parameter switch is ON

Part programs 3 level Program switch is ON

Macro variables 4 level Program switch is ON

Tool compensation

data

Pitch error

compensation data

Tool life files 5 level

CNC least
authority level

4 level

5 level Parameter switch is ON

Remark

3.2.2 File Download (PC→CNC)

Through GSKComm, files in the PC can be transferred to CNC altogether or one by one.

(1) Add files

First, press the type of file to be added (for example, system file, part program file or ladder
diagram file)

Then, press
(shown in the left figure), select the desired file (hold down “shift” key to select more files), then click
“Open” to complete the action.

or right-click, select “Add Files”, a dialog box for adding file will pop up

38

Chapter Machine Ⅲ Tool Debugging-operation

(2) Add multiple files

First, select the project to be transferred; then, click

“Send to CNC”, the following dialog box will pop up. (Shown in the right figure above)

In this dialog box, click the left options to select the files to be transferred. Arrow “－>” points to

the file name saved in CNC, double-click it, you can change the file name.

Click “Start sending” you can transfer the selected file (with the saved file name) into CNC.

(3) Download single file

Select the file to be downloaded, then click
file and select “Send to CNC”, a dialog box will pop up. You can change
the file name to be saved in the CNC, and then click “OK” to transfer
the file.

, or right-click the

or right-click the project and select

3.2.3 Upload File (CNC→PC)

First, select a project, then, click , or select menu "Communication－>Receive Files from

CNC”, a dialog box will pop up, (shown in the left figure below). Select the file to be uploaded, then

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

click “Receive”, a “Browse File” dialog box pops up (shown in the right figure below).

Select the file folder in which the uploaded file to be saved, and click “OK” to upload the selected file.

3.3 Usage of U Disk

The U disk function in GSK988T supports the bi-directional transmission of files involving
machining program, PLC program, parameters, tool compensation data and pitch error compensation
data. It can be operated on three screens: file management screen, program screen and ladder
diagram screen.

3.3.1 File Management Screen

When U disk is already inserted in the USB port, press → to enter into file
management screen.

Under this screen, bi-directional transfer of system files (system parameters, tool compensation
data, pitch error compensation data etc.), ladder diagrams and part programs can be executed. The
procedure is shown as follows:

40

Chapter Machine Ⅲ Tool Debugging-operation

Press

Press

to switch between the system content and U disk content.

softkey to copy the selected program into local directory or U disk directory.

3.3.2 Program Screen

The operation of U disk directory is the same as in the local directory. In
this section, we only introduce the program transfer in U disk. For details,

please refer to GSK988T User Manual.

When the system USB port is inserted with U disk, press

(left figure below), press
into U disk directory screen, operations to the programs in U disk directory such as load, open, copy,
paste, create, save as, delete, rename, search, etc, can be performed.

, the extended softkeys will be displayed. Then, press to enter

to enter into program directory

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

prog

¾ Program bi-directional transmission

① Press

② Move the cursor to the program to be copied through

Then, press

Press

to view the extended softkeys (the right figure above),

to copy the selected program into local directory or U disk directory.

and to switch between the local directory and U disk directory.

and ,

③ When the copied program already exists, a dialog box pops up (see the right figure). Press

“Yes” softkey to cover the existed program; or press “No”, a dialog box

pops up, then

input the program name for saving; press “Cancel” to cancel the operation.

Note 1: When transmission is made from the U disk directory to local directory, the machining

programs can be read only when it is stored in the root directory “NCPROG” file in the U
disk.

Note 2: When transmission is made from local directory to the U disk directory, if the “NCPROG”

file does not exist in the U disk, the file will be created automatically, and the machining

rams will be output to the files.

3.3.3 PLC Screen

When the USB port is inserted a U disk, press on the ladder diagram screen, the

screen is shown in Fig. 3-3-4 (Local directory screen). Press

to switch to the U disk directory

screen, shown in Fig. 3-3-5.

42

Fig. 3-3-4

Chapter Machine Ⅲ Tool Debugging-operation

Fig. 3-3-5

Programs in the U disk directory can be copied to local directory through softkey

versa.

Take the U disk for example, the procedures are shown as follows:

① Press softkey

② Select the ladder diagram programs to be copied through

to enter into U disk directory;

and , then, press

to copy it to the local directory.

Note 1: When PLC transmission is made from the U disk directory to local directory, the PLC

programs can be read only when it is stored in the root directory “LDFILE” file in the U
disk.

Note 2: When PLC transmission is made from local directory to the U disk directory, if the

“LDFILE” file does not exist in the U disk, the file will be created automatically, and the PLC
programs will be output to the files.

3.4 PLC Operation

, vice

Press function key and then press softkey to enter into PLC screen. This screen
includes pages such as version information, monitor, PLC data, PLC state, program directory. Press
corresponding softkeys, you can view the desired content.

After entering the PLC screen, the contents of

is displayed. The version page includes

the information about the PLC version, current running PLC program and the running state, etc.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

3.4.1 PLC Execution and Stop

On PLC screen, press softkey , then press → , the following screen is

displayed:

On this page, you can select PLC program through

running, stop, save, create, delete and backup can be performed.

¾ Execution of PLC programs

and , then press to start running.

44

Select the PLC program through

Note: The current running PLC program is marked with .

and , then operations such as edit,

Chapter Machine Ⅲ Tool Debugging-operation

¾ Stop PLC program execution

Move the cursor to the current running program through
the system will be in no PLC running state.

and , then press ,

3.4.2 PLC Monitoring and Diagnosis

(1) Monitor the PLC program state

On the PLC screen, press softkey
current running PLC program.

to enter to the monitoring display screen for the

You can view the state of current contact, coil conducting ON/OFF and the current value of timer
and counter. When the contact and coil conduction is ON, it is indicated by green color; if not, the

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

color is the background color of the screen. For example: means the contact X0.5 is

conducted,

means the coil Y25.2 is not conducted.

¾ View blocks

On monitoring page, there are four softkeys for monitoring four blocks:

, . Each of them corresponds to a block and the corresponding PLC will be

displayed on the screen.

Note 1: Softkeys for windows 1~4 are shortcut keys which enable quick view of the

corresponding blocks.

Note 2: The blocks corresponding to windows 1~4 can be changed, but the change will not be

effective after power-off. The default block after power-on is the first four blocks in the
PLC programs.

¾ Select block

① Select the screen as needed.

② Press softkey

, the following figure is displayed:

, ,

Press③ keys

④ Press softkey

softkey

to cancel the selection and return to the previous menu.

, , , to select the desired window.

to complete the selection, then, return to the previous menu; press

¾ Search for parameters, commands and network

Select the window in which the command, parameter or network to be searched, i.e. press

, , , to display the corresponding blocks of PLC program,

then, search for the command, parameter or network.

46

Chapter Machine Ⅲ Tool Debugging-operation

② Press softkey

③ Press softkeys

command, network on the corresponding screen, and move the cursor to the corresponding position.

to enter to search page, shown as follows:

, , respectively you can search for the parameters,

④ Press

(2) PLC I/O state diagnosis

On PLC screen, press

following figure.

, to move the cursor to the first line and last line of the block.

and to enter to PLC state display page, as shown in the

¾ View the state of signals

Press softkey

softkey

, the state of signals R, A, K will be displayed.

, the state of signals X, Y, F, G will be displayed on the screen; press

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Press

Press

signals.

or to switch between softkeys X, Y, F, G signal and R, A, K signal.

, , , to view the information about X, Y, F,G signals or R, A, K

3.4.3 PLC Data Viewing and Setting

On PLC screen, press to enter into PLC data state page. It includes the setting of K, D,

DT, DC parameters.

(1) K parameter setting

On PLC data page, press

figure above:

Parameter setting method:

① Press keys

bit to be modified; or press softkey

and move the cursor to the parameter. The meaning of the status bit is displayed at the

bottom of the screen.

② Press

of the selected K parameter status bit.

③ Press

(2) D parameter setting

, , , , , , you can select the parameter statues

repeatedly in K variable status bit to switch between 0 and 1, modify the status

, , , to move the cursor to complete the modification.

softkey to enter into parameter K setting page, shown in the

to input the K variable to be selected, then press

On PLC data page, press

the following figure.

48

to enter to the D parameter setting display page, shown in

Parameter setting method:

Chapter Machine Ⅲ Tool Debugging-operation

① Press keys

modified; or press softkey
move the cursor to the parameter. The meaning of the status bit is displayed at the bottom of the
screen.

② Press

③ Input the modified value, and press

(3) DT parameter setting

On PLC data page, press

the following figure.

, , , , , , you can select the D parameter to be

to input the D parameter to be selected, then press and

to enable the selected D parameter to be modifiable.

key again to finalize the modification.

to enter to the DT parameter setting display page, shown in

Parameter setting method: the same as D parameter setting

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

(4) DC parameter setting

On PLC data page, press

the following figure.

Parameter setting method: the same as D parameter setting

to enter to the DT parameter setting display page, shown in

3.4.4 PLC On-line Modification

On PLC screen, press → → to enter into PLC program directory page, press

and to select the program to be edit, then press softkey to enter into edit page.

You can edit the ladder diagram, symbol table, information display table, initialized data table.

50

Chapter Machine Ⅲ Tool Debugging-operation

(1) View and edit PLC

On the page shown in the above figure, press to enter into PLC display and editing
pages. Shown as follows:

In this figure, the position where the cursor locates is indicated with dashed frame, and the

background color of the network area is darker.

Press

displayed and the block name will be displayed on the upper area of the window.

① Select blocks to the windows

Press

you can select a block to be displayed on the corresponding window.

Press

and return. At this time, the address of corresponding block is shown on the screen. For example,

indicates that the window 1 corresponds to the Level 1 block, when is pressed, the

content of Level 1 block is displayed on the screen.

② Create a new block

Press

, , , respectively, the corresponding blocks will be

, , , according the block to be modified, and then, press

, , , to select the block, then press to complete the action

, , or to select a window on which a block is needed to

be created, then, press

③ Edit program

Select a window to be modified, then press

3-4-14), press

to display the extended keys.

and enter the block name, press to complete the action.

to enter into edit program page (see Fig.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Fig. 3-4-14

Fig. 3-4-15

A. Press , , , to move the cursor to the line to be modified, and press

, keys to move the cursor to the position to be edited.

B. Press

C. Press

to insert a network in front of the network where the cursor locates.

to insert a line behind the line where the cursor locates.

For example:

● Press

Move the cursor to the “Type” selection box at this time, then, press

, the following figure is displayed.

, , ,

to switch between the normally-open contact and normally-closed contact.

52

Chapter Machine Ⅲ Tool Debugging-operation

Press

softkey or “Input” key to complete the action.

● Press softkey

to switch to the “Add/Symb” edit box, and enter the address/symbol, then press

, the following operation is the same as softkey.

● Press softkey

, the following figure is displayed:

Press

figure above, press softkey or press , the following figure is displayed:

, to select the function command to be inserted, for example, ADDB in the

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Press

data, and press to confirm the modification, after all the editing is done, press softkey
to complete the action.

● The operation of other function commands is the same as described above.

You can delete, copy, paste and edit all the components, lines and network at this time. You can

cancel the last step or re-do the step.

● Press softkey

and enter relevant parameters, command, or network. Move the cursor to the position

where the searched parameter (or command, network) locates, then press
move the cursor to the head of a block or end of a block.

● In a similar way, press

● In a similar way, press

or in the edit box to select the parameter to be edited, then enter address or

to switch to the search page, then you can press , , or

, or

to delete component, line or network.

to copy component, line or network. After the copy is complete,

press key

.

● Press

● Press

(2) View and set symbol table

On PLC edit page, press

54

, to move the cursor to the desired network, line or component , then press

to undo last operation. You can cancel up to 20 steps of operation.

to redo the cancellation.

to enter into symbol table display page:

Chapter Machine Ⅲ Tool Debugging-operation

① Press softkeys

symbols to be displayed on the window. The window name and corresponding symbols table name is
shown on the upper area of the screen.

Press softkey to select a symbol table for each window.

Press
there is an empty window, the created symbol table will be displayed on the empty window
preferentially.

Press

displayed as well.

② Press

to create a new symbol table and it is displayed on the current window (Note: if

, the block symbol table is displayed and the corresponding address table is

, the symbol table is displayed, shown as follows:

, , , respectively, you can select the

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Notes for parameter addresses X, Y, DC, DT, T, R are displayed in the symbol table.

Press

Press softkey

Press

Press

address.

Press to insert a null line below the line where the cursor locates.

Press to delete the line where the cursor locates.

③ The operation after press

④ Modify and edit the symbol table (the block symbol table cannot be modified here)

Select the symbol table to be modified, then press

to select the symbol (or address, annotation) to be modified, press

or annotation, then press

(3) View and Modify the message table

, , , , , to select and view all parameter addresses.

to delete the selected symbol table.

to show the extended softkeys.

and enter the parameter address to be searched, locate the cursor to the

, is the same as .

, , , , ,

and input symbol, address

again to complete the modification.

On edit page, press

In this information display table, PLC alarm information address A, corresponding information

number and content are shown. Press
information.

① Modification of information number and content:

to enter to message table, shown as follows:

, , , , , to check these

Press

modified, then press

56

, , , , , to select the information number or content to be

and input the desired information number or content, press again

Chapter Machine Ⅲ Tool Debugging-operation

to complete the modification.

② Search for address and information number:

Press
enter to start searching, then locate the cursor to the searched address or information number.

(4) View and set initialized data table

On edit page, press softkey

or , enter the address or information number to be searched, press

to enter to initialized data table display page:

① K parameter setting

Press to select the window 1 whose corresponding K parameter is shown in the above
figure.

Press
modified, the explanation for the bit in K parameter is displayed on the bottom area of the screen.

Press

② Initialized data

Press

, , , , , to select a bit in the K parameter to be set or

repeatedly, you can set the bit to 0 or 1.

to enter the initData table display page corresponding to window 2.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

③ Data table modification and edit:

Select the desired page by pressing

the address or address value to be modified, the background of the selected value will turn to blue;

press

key again to confirm the modification.

Note: The operation for modifying and editing the initialized data table is the same as the viewing and

and input values through numerical keys (press backspace key to delete), then press

setting of symbol table. For details, please refer to the “3.4.3 (2)

or ; press , , , to select

View and set symbol table”.

3.4.5 PLC Program Transmission

PLC program transmission is subject to authority above the 2nd level.
There are two method of PLC program transmission:

1. Transmit with GSKComm-M. For details, please refer to section 3.2 in this chapter.

2. Transmit PLC program one by one on PLC screen through U disk, or, make bulk transmission

on file management screen. For details, please refer to section 3.3 in this chapter.

3.5 CNC Diagnosis

Press to enter to information screen, then press to enter to diagnosis page,

press

58

to enter to CNC diagnosis page.

Chapter Machine Ⅲ Tool Debugging-operation

On the system diagnosis page, contents such as keyboard diagnosis, state diagnosis, and

auxiliary function parameter are included. They can be viewed through

, . You can press to lock to the current screen in case of mis-operation.

On CNC diagnosis display page, there are two lines at the bottom of the screen displaying the
diagnosis details: the first line shows the diagnosis number; the second line shows the explanation of
a bit in the parameter where the cursor locates.

The diagnosis information and corresponding number is shown as follows:

¾ System keyboard diagnosis information (number: 0-7)

It can diagnose all the keys on the system keyboard. Each key is in either pressed or
released state. It is used to diagnose whether the keyboard is in good condition.

¾ Feed axis diagnosis information (number:10-29)

It includes the input/output state of servo drive unit connected with the feed axis, the pulse sent
from feed axis to FPGA, the pulse sent from FPGA to servo drive unit, and the accumulative errors of
the feed axis pulse (the difference between the FPGA received and sent pulse). It is used to diagnose
whether the feed axis is in good working condition.
¾ Pulse encoder diagnosis information (number:30~33)

It includes the rotation direction of the two-channel pulse encoder, Z signal state, A,B phase
signal state and the current counting pulse value. It is used to diagnose whether the pulse encoder is
in good working condition.
¾ MPG diagnosis information (number: 40-43)

It includes the rotation direction of the two-channel MPG, A, B phase signal state and current

counting pulse value. It is used to diagnose whether the encoder is in good working condition.

¾ Spindle diagnosis information (number: 50~52)

It includes the state of two-channel spindle alarm signal, tapping signal, enable signal and ready
signal.

¾ Machine tool panel diagnosis information (number: 60-62)

It includes the accumulative errors number, consecutive errors number and repeated number of

the machine tool panel. It is used to diagnose whether the machine tool panel is in good working

, , , ,

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

condition.

¾ Edit keyboard diagnosis information (number: 63-65)

It includes the accumulative errors number, consecutive errors number and repeated number of

the edit keyboard. It is used to diagnose whether the edit keyboard is in good working condition.

3.6 Servo Diagnosis

On system screen, press to enter to diagnosis page, then press to enter to

servo diagnosis page.

GSK988T servo diagnosis module provides the following functions:

It performs real-time monitoring to system controlled axes through servo communication
feedback data, so the operator can know about the working state of some devices such as servo,
motor etc.

(1) When the servo is in position control mode, the information displayed includes the

command pulses received by the servo, the feedback pulses obtained from the motor
encoder, actual rotation speed of the motor, servo internal current, detected temperature
in the servo.

(2) When the servo is in speed control mode, the displayed information includes the specified

rotation speed received by the servo, actual rotation speed obtained from the motor,
command pulses received by the servo, servo internal current, detected temperature in the
servo ( spindle encoder value is displayed).

(3) The I/O sate when servo is connected with system.

Explanations for various data items on servo diagnosis screen:

: Current selected axis name

: The number of the slave connected to the axis

: The connection state of servo communication link layer

: The servo control mode

: The position pulses received from the system (in position control mode)

60

: The speed command value received from the system (in speed control mode)

Chapter Machine Ⅲ Tool Debugging-operation

: The position pulses feedbacked by the servo

: The actual rotation speed of the motor

: The current value of spindle encoder (in spindle or C axis control mode)

: The servo working current value at present

: The detected temperature of the servo inside

it to reset the communication link. If the connection still cannot be done, turn on the power of servo
and system again.

: The servo input point value
: The servo output point value

: Details of the servo input and output points where the cursor

Axis switching: Press

among X, Z, S axis

: When some axes are not connected or the servo communication is erroneous, press

located

, , to switch the displayed servo parameter

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

CHAPTER IV MACHINE DEBUGGING-FUNCTIONS

4.1 Emergency Stop and Hardware Limit

GSK988T is equipped with the software limit function; for safety, it is suggested to adopt the
hardware limit function at the same time. Install the limit switches in positive and negative directions
on axes; the connection is shown in the following figure:

Fig. 4-1-1

In
the correctness of the displayed alarm and the validity of the overtravel release button;

when it overruns or the emergency stop button is pressed, CNC alarms “emergency stop”. The

alarm can be cleared through pressing the
shield PLC emergency stop parameter which makes the switch invalid, and then press the resetting
key to clear the emergency stop limit alarm, and the axis moves toward the worktable in the reverse
direction and is off from the limit switch.

parameters

Standard

parameters

or mode, slowly move each axis to verify the validity of the overtravel limit switch,

and the axis moves in the reverse direction, or

Relevant Parameter

CNC

PLC

Parameter

No.

3003 #7

K0010 #7

Bit Meaning Remark

ESP emergency stop alarm signal (X0.5)

0: Emergency stop alarm occurs when the

input signal is 0 (low-level signal)

1：Emergency stop alarm occurs when the

input signal is 1 (high-level signal)

External emergency stop alarm signal (X0.5)

0: Emergency stop alarm occurs when the

signal is low-level

1：Emergency stop alarm occurs when

signal is high-level

These two
parameters
should be set
consistently.

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Chapter IV Machine Debugging-Functions

4.2 Basic Axis Parameters Setting

4.2.1 Axis Property

(1) Axis name

The controlled axis number of 988T is 2, the extended controlled axis number is 5 (including Cs

axis), and the linkage controlled axis number is 3.

Relevant Parameter

No. Meaning Remark

8130 Total controlled axis

This parameter value cannot

1010 CNC controlled axis number

1020 Name of each axis

1022 Axis properties in basic coordinates

Servo axis number of each axis The set axis number should

1023

(2) Axis unit

After the above parameters are set, you can set the axis names, input/output unit (metric or inch)

and incremental system as requirement.

Relevant Parameters

No. Bit Meaning

0000 #2

1001 #0

1004 #1

1006 #3

3401 #0

(3) Axis type

During machining, you can set the axis as linear axis or rotary axis according to the machining
requirement.

Input unit

0: metric 1: inch

The least movement unit of the linear axis:
0: metric (metric machine) 1: inch (inch machine)

Set the least input increment and least command increment
0: 0.001mm 1: 0.0001mm

Set the movement amount of each axis
0: by radius 1: by diameter

For the addresses which decimal points can be used, when the decimal
point is ignored, the setting is as follows:

0: as the minimum setting unit 1: as mm, inch, s

Relevant Parameter

be greater than parameter
No.8130

The axis names cannot be
the same

correspond to the axis
number of the rear cover
interface.

No. Bit Meaning

Whether the least input increment of rotary axis is 10 times of the

1004 #6

1006 #1, #0 00: Linear axis 01: rotary axis (A Type) 11: rotary axis (B type)

least command increment:
0: No 1: Yes

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

1008 #0

1008 #1

Whether the circle display function of rotary axis is valid:

0: invalid 1: valid

The rotation direction of absolute command is :
0: the direction closer to the object 1: specified by command value symbol

Relative coordinate is :

1008 #2

0: does not cycle by the movement amount per rotation

1: cycles by the movement amount per rotation

1260 Movement amount per rotation of each rotary axis

4.2.2 GSKLink Communication Setting of Axis and Servo

When GSKLink communication between feed and spindle servo drive unit is to be executed, the
servo slave number and communication baudrate need to be set.

Note 1: The slave number corresponding to the servo communication cannot be

repeated. The baudrate of servo should be consistent with the system
communication baudrate; otherwise, the communication cannot be set up.

Note 2: The parameters and slave number and baudrate in the servo should be set

before the servo is connected to the GSKLink, and should be modified manually
in the drive unit (valid after power-on again).

Relevant Parameter

Type No. Bit Meaning Remark

System servo communication

GSK
988T

System

CNC

parameter

DAT
2000C
Series

Servo

DAP03C

DAY3025C

9000 #0

9010

function is :

0: invalid 1: valid

System servo communication
baudrate

Slave number corresponding to

9011

the servo communication of
each axis

Slave number of analog

9012

spindle communication
(SIDS1)

PA58

PA59

GSKLink communication servo
slave number

GSKLink communication
baudrate

PA61 Drive unit type 101: 2050C; 102: 2075C

PA19

PA20

GSKLink communication servo
slave number

GSKLink communication
baudrate

Be consistent with the servo baudrate

The slave number cannot be repeated.

Corresponds to the CNC parameter
No. 9011

Be consistent with the CNC parameter
No. 9010

Corresponds to the slave number set
by CNC parameter No. 9012, 9013

Be consistent with the baudrate set by
CNC parameter 9010

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Chapter IV Machine Debugging-Functions

4.3 Servo Related Setting

4.3.1 CNC Servo Parameter Setting

After the connection between system and servo is done, and the power is on, you can set the
high-level or low-level servo alarm, encoder type, pulse output type, pulse output direction of each
axis and axis movement direction. The procedure is as follows:
① According to the alarm logic level of servo drive unit set corresponding alarm level of servo
axis through parameter NO.1816#0 (ISAx).
② Select the pulse output method of current axis through parameter No.1811#0 (ABPx).
GSK988T supports two methods of pulse command output, one is + direction pulse output; the other
is orthogonal two phases (AB phase) pulse output. The parameter should be set correctly.
③ According to the encoder type of the servo motor set whether absolute encoder is used on
servo through parameter No. 1815#5 (APCx).
④ According to the transmission ratio of the machine set correct gear ratio CMR/DMR (through
parameter No. 1816 and No. 1820) to make the movement distance be consistent with the specified
value (for details, see follow-up sections).
⑤ When the machine movement direction is inconsistent with the movement command,
inverse the output movement direction of servo axis command by setting parameter No. 1811#2
(PODx).
⑥ When the detection direction of absolute encoder is opposite to the actual direction, adjust it
through parameter No.1815#0 (APRx). (This detection method is: when the reference point is set,
specified axis moves along + direction +U, and +U is displayed in the machine coordinate system,
turn on the power again; if –U is displayed in the machine coordinate system, then, the detection
direction of absolute encoder is opposite to the actual direction.)

Note 1: In AUTO or MANUAL mode, when the specified axis direction is opposite to the

actual feeding direction, modify parameter No. 1811#0.

Note 2: In manual mode, when the manual feed direction is opposite to the actual feeding

direction (correct in AUTO or EDIT mode), modify PLC data parameter K8.0~K8.4.

No. Bit

1811 #0

1811 #2

GSK

988T

1815 #0

System

parameter

1815 #5

1816 #0

PLC data

parameter

K8.0～K8.4

Relevant Parameter

Meaning

Pulse output type:

0 : pulse + direction 1: AB phase pulse

Pulse output direction:

0: Not reversed 1: reversed

When absolute encoder is used, the direction of position
detector:

0: Not reversed 1: reversed

Position detector is:

0: absolute position detector 1: not absolute position detector

Servo alarm signal level:

0: high-level alarm 1: low-level alarm

Manual movement direction of each axis is:

0: not reversed 1: reversed

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

4.4 Gear Ratio Adjustment

Electronic gear ratio enables the move distances of machine tool slide be consistent with

the specified distance (move distance of the machine coordinate). If the axis is set in radius

system (radius or diameter programming is set by parameter No.1006#3), the actual move distance
of the machine equals to the move distance displayed on the machine coordinate system; if the axis
is set in diameter system, the actual move distance of the machine is the double of the move distance
displayed on the machine coordinate system.

Please note that the electronic gear ratio is related to both the setting of CNC gear ratio and

servo drive unit gear ratio.

Relevant Parameters

No. Bit

0000 #2

1004 #1

1006

1006 #3

1816

1820 Set the command multiplying ratio of each axis

#1、#0

#6、#5、#4

Input unit:

0: metric 1: inch

Least input increment and least command increment:

0: ISB system 1: ISC system

Linear axis or rotary axis

00: linear axis 01: rotary axis (A type) 11 : rotary axis (B type)

Movement amount of each axis is

0: specified by radius 1: specified by diameter

Set the detect multiplying ratio of each axis

Meaning

Incremental System

IS－B IS－C

Metric

machine

Inch

machine

Input

Metric

Inch

Metric

Inch

Rotary axis 0.001deg 0.001deg 0.0001deg 0.0001deg

Radius/

Diameter

Diameter 0.001mm 0.0005mm 0.0001mm 0.00005mm

Radius 0.001mm 0.001mm 0.0001mm 0.0001mm

Diameter 0.0001 inch 0.0005mm 0.00001 inch 0.00005mm

Radius 0.0001 inch 0.001mm 0.00001 inch 0.0001mm

Diameter 0.001mm 0.00005 inch 0.0001mm 0.000005 inch

Radius 0.001mm 0.0001 inch 0.0001mm 0.00001 inch

Diameter 0.0001 inch 0.00005 inch 0.00001 inch 0.000005 inch

Radius 0.0001 inch 0.0001 inch 0.00001 inch 0.00001 inch

Least setting

increment

Least
command
increment

Least setting

increment

Least command

increment

66

4.4.1 Gear Ratio Calculation

Formula

Chapter IV Machine Debugging-Functions

increment command Least ratio Gear ××=

revoltion per pulses encoder

Lead

Note: Least command increment is the minimum unit of command from CNC to machine tool,
and the minimum increment of tool movement.
Pulse/rev ＝ Encoder line number (absolute encoder)

＝ 4 × Encoder line number (incremental encoder)

ZM ：Teeth number of lead screw gear

Z

M

Z

D

ZD ：Teeth number of motor gear

Example：

When a machine is equipped with GSK988T and DAT2050C, and the ISC system is applied,

the X axis is programmed in diameter system, the lead is 6mm, Z axis is programmed in radius

system, the lead is 8mm; the motor is connected with X, Z axis lead screw directly (Z

17

17-bit absolute encoder is applied (the encoder line number is 2
corresponding gear ratio of X, Z axis is as follows:

X axis:

Least command increment: 0.00005mm (ISC system, programmed in diameter)

increment commandLeast ratioGear

, i.e. 131072), the calculation of

revoltionper pulsesencoder

××=

Lead

2048

00005.0

131072

6

Z axis:

Least command increment: 0.0001mm (ISC system, programmed in radius)

1

=××=

1875

1

increment commandLeast ratioGear

revoltionper pulsesencoder

××=

Lead

1024

0001.0

131072

8

1

=××=

625

1

Z
Z

Z
Z

M：ZD

M

D

M

D

=1：1);

4.4.2 Gear Ratio Setting

Parameter Setting of Gear Ratio

ratio Gear:CNC

=

No.1820):(CMR ratio gmultiplyin Command

No.1816):(DMR ratio gmultiplyin Detect

ratio Gear:Servo

=

When the numerator is greater than the dominator in CNC electronic gear ratio (CMR/DMR), the
CNC permitted maximum speed will be decreased; when the numerator is smaller than the dominator,
the CNC position accuracy will be decreased. To ensure the target accuracy and speed, when digital
servo with electronic gear ratio function is matched, it is advised to set the CNC electronic gear ratio

(PA12) ratio gmultiplyin command pulse Position

(PA13) ratio divisionfrequency command pulse Position

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

to 1:1, and set the calculated electronic gear ratio into digital servo.
Example: (the gear ratio is the one in the example of Gear Ratio Calculation)

X axis

CNC gear ratio setting

CNC electronic gear ratio is set as 1:1, i.e. CMR/DMR=1:1
Setting value of CMR (Parameter No. 1820) is 2.
Setting value of DMR (Parameter No.1816)(DM3x：DM2x：DM1x) is 001.

Servo gear ratio setting
The servo gear ratio is set as 2048 / 1875.
Setting value of PA12 is 2048.
Setting value of PA13 is 1875.

Z axis

CNC gear ratio setting

CNC electronic gear ratio is set as 1:1, i.e. CMR/DMR=1:1
Setting value of CMR (Parameter No. 1820) is 2.
Setting value of DMR (Parameter No.1816)(DM3x：DM2x：DM1x) is 001.

Servo gear ratio setting
The servo gear ratio is set as 1024 / 625.
Setting value of PA12 is 1024.
Setting value of PA13 is 625.

4.5 Acceleration/Deceleration Characteristic Adjustment

As the acceleration/deceleration time constant increases, the acceleration/deceleration process
slows down, the impact to machine tool decreases, and the machining efficiency decreases; and vise
versa.

When the time constant is the same, the higher the start/end speed of acceleration/deceleration

is, the greater the impact will be, so are the machining efficiency; and visa versa.

The principle of acceleration/deceleration characteristics adjustment is: to properly reduce the
acceleration/deceleration time constant and increase the start/end speed of acceleration/deceleration
to improve processing efficiency in the condition that the drive unit won’t issue an alarm, the motor
can work without the loss of steps and no obvious impact occurs to the machine tool. If the
acceleration/deceleration time constant is too small or the start/end speed is set too high, it can easily
lead to drive unit alarm, motor step loss or machine tool vibration.

篇

Note: when parameter No.1601#4=0, at the intersection point of cutting feed paths, the feedrate

should be decreased to the start speed of the acceleration/deceleration, then, increased to
the specified speed of the adjacent block. Accurate position of intersection point can be
achieved in this way, but it may lower down the machining efficiency.

When parameter No.1601#4=1, two adjacent cutting paths perform smooth transition in

acceleration/deceleration method directly. The feedrate does not necessarily decrease to
the start speed when the previous path ends. An arc transition is formed at the intersection
point (inaccurate position). This kind of transition way allows great surface smoothness
and higher machining efficiency.

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Chapter IV Machine Debugging-Functions

Relevant Parameter

No. Bit Meaning

1420

1421

1422

1423

1424

1601 #4

1610 #0

1610 #4

1620 Constant T during linear acceleration/deceleration of each axis

1622 Acceleration/deceleration time constant of cutting feedrate after interpolation

1623 Exponential acceleration/deceleration FL speed of cutting feedrate

1624

Rapid traverse rate of each axis

The minimum speed of rapid traverse override

Maximum cutting feedrate of all axes

Manual feedrate of each axis

Manual rapid traverse rate of each axis

During rapid traverse, the blocks are:

0: not overlapped (accurate) 1: overlapped (smooth transition)

The acceleration/deceleration of cutting feedrate (including dry run feeding) is:

0: exponential type 1: linear type after interpolation

The acceleration/deceleration of manual feeding is :

0: exponential type 1: linear type or bell-shaped type after interpolation

Acceleration/deceleration time constant of manual feedrate after interpolation

1625 Exponential acceleration/deceleration FL speed of manual feedrate

1626 Acceleration/deceleration time constant during thread cutting cycle

1627 Exponential acceleration/deceleration FL speed during thread cutting cycle

4.6 Reference Point and Software Limit

GSK988T supports three kinds of method to set machine zero point (also called reference point):
reference point setting without dogs, reference point setting with dogs and absolute encoder
reference point setting.

Reference Point Setting System Parameter Setting

absolute encoder

reference point setting

reference point setting

without dogs

reference point setting with

dogs

Parameter No.1815#5 (APCx) is set to 1

Parameter No.1815#5 (APCx)is set to 0
Parameter No.1002#1 (DLZ) is set to 1 or parameter No.1005#1
( DLZx) is set to 0 (either one of them is set to 1)

Parameter No.1815#5 ( APCx) is set to 0
Parameter No.1002#1 DLZ is set to 0 and parameter No.1005#1
DLZx is set to 0.

Note 1: When absolute encoder is used, after a reference point is set, it will be saved

automatically after power-off, so it is not necessary to set the reference point the
next time.

Note 2: When reference point is set with/without dog, the setting should be executed

every time after power-on.

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Relevant Parameter

No. Bit Meaning

When the reference point is not set, in AUTO (MEM, DNC OR

1005 #0

MDI) mode, if movement commands other than G28 is
specified, the system will

0: issue an alarm 1: not issue an alarm

1006 #5

Set reference point return direction of each axis

0: positive direction 1: negative direction

After the manual reference point return is done, the local

GSK988T

System

Parameter

PLC Data
Parameter

1201 #2

1240

1241

1242

1243

1425

Set the FL speed after deceleration during reference point

K12.2

coordinate system is:

0: not cancelled 1: cancelled

Set the coordinate value of the 1

st

reference point in machine
coordinate system

Set the coordinate value of the 2

ndt

reference point in machine
coordinate system

Set the coordinate value of the 3

rd

reference point in machine
coordinate system

Set the coordinate value of the 4

th

reference point in machine
coordinate system

return

Whether the direction keys of zero-return operation is
automatically locked:

0: No 1: Yes

4.6.1 Reference Point of Absolute Encoder Setting

When the machine is equipped with the absolute position encoder and its reference point return
function is valid, it requires setting the absolute position encoder reference point while the system
doesn’t set the reference point or readjust the reference point. After setting the reference point, the
system automatically saves the reference point position after power-off, therefore, it doesn’t require
setting the reference point position, again when it powers on in the next time.

The steps of setting the reference point of absolute encoder are shows as follows:

1. In mode of or mode, the axis carriage is moved to the reference point to be set.

2. The system parameter APZx (NO.1815#4)is set as 0, cut off power supply, and power on,

again, the system alarms.

3. Press

4. Press the switches
point return is performed.

on the panel.

related to the reference points, then the reference

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Chapter IV Machine Debugging-Functions

5.,The reference point return finishing indicator (operational panel indicator)

is on, the reference point return finishes, the system saves the

current encoder position, automatically sets the parameter APZ x as 1.

Relevant Parameter

No. Bit Meaning

When absolute encoder is used, the direction of position detector

1815 #0

is:

0: not reversed 1: reversed

When absolute encoder is used, the machine position and the

1815 #4

position of absolute position detector is

0: inconsistent 1: consistent

Position detector:

1815 #5

0: uses absolute position detector 1: does not use absolute position
detector

4.6.2 Reference Point Setting with Dog

When the reference point return without dogs function is set invalid (i.e. the reference point
return with dogs is valid), reference point return can be performed when the machine is installed
deceleration switch. After the tool returns to the reference point, LED indicator lights up, and
coordinate system is set automatically.

The procedure of setting the reference point free of block is shown as follows:

1. Confirm that the overtravel limit switch is valid.

2. Press

3. To reduce zero-return speed, adjust the rapid traverse override

to switch the working mode to reference point return mode.

to the low

gear.

4. Press the corresponding axis icon on

, the system will read axis and the

direction selection signal, then, reference point return is executed.

5. When the carriage moves to the deceleration point at the rapid traverse rate, and the
deceleration signal DECx is valid (the valid level of a signal is set by parameter No. 3009#5 DECx),
the speed will decrease to 0, then, the carriage keeps moving toward the reference point at the speed
set by parameter No1425.

6. When the tool leaves the position of deceleration switch, set the deceleration signal DECx to 1,
and the system detects the one-rotation signal nPC.

7. After the first nPC signal is detected, set the signals ZPx (reference point return finish signal)
and ZRFx (reference point setting signal) to 1, the reference point return indicator

lights up, reference point return is done.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

y

Note: Usually, the machine zero return dog is installed at the maximum stroke point. The effective

stroke should be over 25mm to ensure enough deceleration distance and the accuracy of
zero return. The higher the machine zero return speed is, the longer the zero return
collision block will be. Otherwise, the carriage will go through the collision block due to
CNC acceleration/deceleration or machine inertial, thus, affects the accuracy of zero return.
In addition, make sure that during the process of zero return the carriage will not be
intervened b

other parts of the machine tool, for the sake of security.

The connection method of AC servo motor is shown in the following figure. Stroke switch and

servo motor one-rotation signal are used.

Direction of mechanical

zero return

Limit switch

Dog installed in the

mechanical sliding

board

Connect to +24V
Connect to DECn signal

Fig 4-2

When machine zero return is performed after the deceleration switch is released, it should be
noted that the encoder one-rotation signal should not be at the critical point, and be reached after
half-revolution of the motor. This method is to improve the machine zero point return accuracy. The
dog position can be tuned to reduce the error of zero point return.

4.6.3 Reference Point Setting without Dog

When the system sets reference point without dog function valid, the machine can perform
reference point return without the installation of deceleration switch. After reference point return is
done, the LED indicator lights up and the coordinate system is set automatically.

1. Axis moves along the reference point return direction, and stops close to the reference point,

rather than surpasses it.

2. Press

3. Select corresponding feeding axis and direction on
direction signal Jx to 1, reference point return is executed.

4. The tools moves towards the reference point along the direction set by parameter No. 1006#5

at the speed set by parameter No. 1425.

5. After the first PC signal is detected, set ZPx (reference point return end signal) and ZRFx

(reference point setting signal) to 1, the LED indicator
reference point return is done.

and set the reference point selection signal ZRN to 1 manually;

, and set the axis and

lights up and

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Chapter IV Machine Debugging-Functions

A: the position before the execution of reference point return without dog
B: the position after the reference point return is executed along the negative direction, i.e. the

position where the first PC signal is generated after the A point moves along the negative direction.

C: the position after the reference point return is executed along the negative direction, i.e. the

position where the first PC signal is generated after the A point moves along the negative direction.

Relevant Parameters

No. Bit Meaning

1002 #1

1002 #3

1005 #1

1300 #6

The function of reference point return without dog is

0: invalid 1: valid (for all axes)

The G28 command when reference point is not set:

0: reference point return with dog 1: P/S alarm occurs

The function of reference point setting without dog is:

0: invalid 1: valid

Whether the first stroke check is performed before manual reference
point return after LZR power-on:

0: Yes 1: No

4.6.4 Setting of Stored Stroke Check

There are three stored stroke check are provided in GSK988T system: stored stroke check 1,

stored stroke 2 and stored stroke 3. Tool cannot enter the areas specified by them.

Stored stroke limi t 2
(inner side is forbidden
area)

Stored stroke limit 3

Stored stroke limit 2 (Outer side
is forbidden area)

Stored strok e limit 3

:Tool forbidden area

Stored stroke check 1:

Parameters (No.1320, 1321 or No. 1326, 1327) set the boundary. Outside the area of the set

limits is a forbidden area. The machine tool builder usually sets this area to maximum stroke.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Stored stroke check 2: (G22 G23)

Parameters (No.1322, 1323) or commands set the boundaries. Inside or outside the area of the
limit can be set as the forbidden area. Parameter No. 1300#0 selects either inside or outside as the
forbidden area. In case of program command a G22 command forbids the tool to enter the forbidden
area, and a G23 command permits the tool to enter the forbidden area. Each of G22 and G23 should
be command independently of another command in a block.

Stored stroke check 3:
Parameters No. 1324, No.1325 set the boundary. The inside area of the 3 limits is forbidden

area.

Note：If the two points for specifying a forbidden area are identical, all areas are handled as

forbidden areas for stroke check 1.

If two points for specifying a forbidden area are identical, all areas are handled as

movable areas for stored stroke check 2, 3.

Alarm displaying time:

Parameter No.1300#7 (BFA) selects whether an alarm is displayed immediately before the tool

enters the forbidden area or immediate after the tool has entered the forbidden area.

Releasing the alarm:

If the tool enters a forbidden area and an alarm is generated, the tool can be moved only in the

backward direction. To cancel the alarm, move the tool backward until it is outside the forbidden area
and reset the system. When the alarm is cancelled, the tool can be moved both backward and
forward.

Relevant Parameter

No. Bit Meaning

1300 #0

1300 #2

1300 #5

Parameters (No.1322, 1323) set the forbidden area for stored stroke check 2 to:

0: inside area 1: outside area

The signal EXLM (stored stroke check switch signal) is :

0: invalid 1: valid

Stroke check 3 releasing signal RLSOT 3 is:

0: invalid 1: valid

Whether the first stroke check is performed before manual reference point return

1300 #6

after power-on:

0: Yes 1: No

The alarm is issued:

1300 #7

1310 #0

1310 #1

0: before the tool enters the forbidden area

1: after the tool enters the forbidden area

Whether stored stroke check 2 is performed on each axis:

0: no 1: yes

Whether stored stroke check 3 is performed on each axis:

0: no 1: yes

1320 Coordinates (PC1) of stored stroke check 1 positive boundary

1321 Coordinates (NC1) of stored stroke check 1 negative boundary

1322 Coordinates (PC2) of stored stroke check 2 positive boundary

1323 Coordinates (NC2) of stored stroke check 2 negative boundary

1324 Coordinates (PC3) of stored stroke check 3 positive boundary

1325 Coordinates (NC3) of stored stroke check 3 negative boundary

1326 Coordinates II (PC12) of stored stroke check 1 positive boundary

1327 Coordinates II (NC12) of stored stroke check 1 negative boundary

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Chapter IV Machine Debugging-Functions

4.7 Pitch Error Compensation

If the pitch error compensation value is defined, the pitch error compensation of each axis can be

compensated based on the detection units of each axis.

Set the pitch error compensation data for each compensation position, and its compensation
position is set based on the space between each axis. The compensation origin is the reference
position of the tool return.

When the pitch error compensation is performed, the following parameters must be set:

Parameter 3620: The position number of the compensation at the reference point of each axis.

Parameter 3621: The minimum position number of each axis pitch error compensation

Parameter 3622: The maximum position number of each axis pitch error compensation

Parameter 3623: The magnification of pitch error compensation

Parameter 3624: The interval of each compensation position.

Compensation Position Number 21 22 23 24 25 26 27

Set Compensation Value -3 +1 +1 +1 +2 -1 -3

Define the compensation position: To set the compensation position for each axis, specify the
positive or negative direction for compensation based on the reference point. If the machine stroke
exceeds the specified range in positive or negative direction, the screw pitch error compensation
does not work.

Compensation position number: In screw pitch error compensation setting screen, there are
1024 compensation positions (0~1023) can be used. The parameter can be used to assign position
number to each axis. Set compensation position number (parameter No.3620), minimum position
number (parameter No. 3621) and maximum position number (parameter No. 3622) of each axis.

For example:

1. Linear axis

Machine stroke

Interval of the screw pitch error compensation positions：50mm

Compensation position number of the reference point: 70

After the above definition is finished, the furthest compensation position number in negative
direction is as below:

：－

400mm~＋800mm

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

The compensation position number of the reference point – (machine stroke in negative

direction/space between compensation positions) = 70－400/50+1=63

The furthest compensation position number in positive direction is as below:
Compensation position number of the reference point + (machine stroke in positive direction/

space between compensation positions) ＝70＋800/50=86

The corresponding relation between the machine and the compensation point position number is

shown as follows:

Parameter Setting Value

3620: Parameter point compensation number 70

3621: Minimum compensation position number 63

3622: Maximum compensation position number 86

3623: Compensation magnification 1

3624: Space between the screw pitch error compensation
positions

2. Rotary axis
Movement value/ revolution: 360°
Space between the screw pitch error compensation positions: 45°
Compensation position number of the reference point: 80
After defining the above parameter, the furthest compensation position number in negative

direction of the rotary axis is the compensation position number of the reference point.

The furthest compensation position number in positive direction is as follows:
The compensation position number of the reference point + (movement value of each revolution/

space between compensation positions) = 80+360/45=88

The corresponding relation between the machine coordinate and the compensation position

number is as follows:

The parameter is set as follows:

Parameter Setting value

3620: Compensation number of the reference point 80

3621: Minimum compensation position number 80

3622: Maximum compensation position number 88

3623: Compensation magnification 1

3624: Space between screw pitch error compensation positions 45000

50000

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Chapter IV Machine Debugging-Functions

For the rotary axis, there may result in the position offset if the sum of the compensation value of
positions 81~88 is not 0. The sum is the accumulation of screw pitch error compensation value of
each revolution. Moreover, at the compensation positions 80 and 88, the same compensation value
must be set.

For example:

No. of Compensation

Position

Set Compensation value +1 -2 +1 +3 -1 -1 -3 +2 +1

Set pitch error compensation value

80 81 82 83 84 85 86 87 88

¾ In system window, press

to enter into pitch error compensation window, shown as

follows:

You can view and set corresponding pitch error compensation value in this window.

¾ Press

¾ Press

, or move the cursor through , , , to select the

value to be set; or, press

to search for the pitch error compensation number, and

move the cursor to the value to be modified.

, the selected compensation can be modified, input the desired value, then press

to complete the modification.

Note: The compensation value and interval of compensation point are related to the
programming method (diameter programming/radius programming affects the least
command increment). When the axis movement is programmed in diameter, the parameter
value should be set in diameter; when the axis movement is programmed in radius, the
parameter value should be set in radius. The unit should be detection unit.

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

Relevant Parameter

No. Bit Meaning

3620 Pitch error compensation number of reference points

3621

3622

3623 Pitch error compensation magnification

3624 Intervals of compensation points

3628 #4~#0

Pitch error compensation number of the farthest ends in negative
direction

Pitch error compensation number of the farthest ends in positive
direction

Setting value of pitch error compensation pulse frequency (in the form
of BCD code)

4.8 Backlash Compensation

When the machine tool moves backward inverse momentum loss will occur due to the error of
transmission mechanism, thus affects the machining accuracy. To reduce such error, backlash
compensation function is provided in this system.

The backlash compensation value is related to the programming method (diameter
programming/radius programming affects the least command increment). When the axis movement is
programmed in diameter, the parameter value should be set in diameter; when the axis movement is
programmed in radius, the parameter value should be set in radius. The unit should be detection unit.

Detection Unit = Least command increment/command multiplication (CMR)

The backlash compensation should be performed in a proper way to improve the machining

accuracy. It is advised to use dialgauge, micrometer or laser detector rather than MPG or step
method to measure the backlash. The methods are shown as follows:

The setting method of backlash compensation during cutting feed

Programming:

O0001;

N10 G01 W10 F800;

N20 W15;

N30 W1;

N40 W-1;

N50 M30.

Set the backlash compensation value to 0 before measuring
Run a single block and find the measuring benchmark 1 after twice locations, record the current

data, then, move further for 1mm and move backward for 1mm to benchmark 2, read the current data.

Backlash compensation value=| data at benchmark 1- data at benchmark 2| ; then, convert the

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Chapter IV Machine Debugging-Functions

calculated data to detection unit and input the CNC data parameter No. 1851.
Data 1: the dialgauge data read at benchmark 1
Data 2: the dialgauge data read at benchmark 2
Detection unit= Least command increment/CMR
For example:

When IS-B system is set (parameter No.1004#1 ISC is set to 1) and the metric system is
selected (parameter No.1001#0 INM is set to 0), if parameter No. 1820 (used to set the command
multiplication) is set to 2, then, the system command multiplication CMR=1.

X axis: detection unit=least command increment/CMR=0.00005mm/1=0.00005mm

Z axis: detection unit=least command increment/CMR=0.0001mm/1=0.0001mm

If the backlash compensation value of X axis detected by dialgauge is 0.0150mm, the parameter
No. 0851 is set to 300; If the backlash compensation value of Z axis detected by dialgauge is

0.0300mm, the parameter No. 0851 is set to 300;

To improve the compensation accuracy, the backlash compensation value can also be set to
rapid traverse and cutting feed. First, set parameter No.1800#4 (RBK) to 1, (cutting feed and rapid
traverse will be performed independently), then, set the backlash compensation value to rapid
traverse through parameter No.1852.

For example,

If the detected backlash compensation during cutting feed is A, and the detected backlash
compensation during rapid traverse is B, according to different feeding method and move direction,
the compensation value is shown in the following table:

Feeding method

Move direction

The same

direction

Opposite

direction

1. a= (A-B)/2

2. The positive or negative of the compensation value determines the move direction. (P80)

Cutting feed

to cutting feed

0 0 ±a ± (-a)

±A ±B ± (B+a) ± (B+a)

Rapid traverse

to rapid

traverse

Rapid traverse

to cutting feed

Cutting feed to

rapid traverse

The setting steps of backlash compensation parameters are shown as follows:

① Whether the backlash compensation is performed respectively during cutting feed and rapid

traverse determines the setting of parameter No.1800#4 (RBK).

0: not performed 1: performed

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

② Measure the backlash compensation value in the above method, and save the results in

parameter No. 1851 and No. 1852 (when parameter No. 1800#4 RBK is set to 1). Note that the
parameter unit should be detection unit.

③ After the backlash compensation value is set, set the backlash compensation output method

according to parameter No. 1800#7 (BDEC), 0: fixed pulse frequency output 1: output
according to acceleration/deceleration characteristics. No. 1800#4.

④ When the parameter No. 1800#7 (BDEC) is set to 0 (fixed pulse frequency output), parameter No.

1800#6 (BD8) sets the output pulse frequency.
0: the set frequency 1: 1/8 of the set frequency.
The set frequency for compensation is set by parameter No. 1853.

⑤ When parameter No. 1800#7 (BDEC) is set to 1 (according to acceleration/deceleration

characteristic output), the valid time constant can be set by parameter No. 2071.

Relevant Parameter

No. Bit Meaning

Whether backlash compensation is performed respectively during

1800 #4

1800 #6

1800 #7

1851 Backlash compensation value

1852 Backlash compensation value during rapid traverse

1853 #0~#4 Setting value of backlash compensation pulse frequency

2071

cutting feed and rapid traverse
0: No 1: Yes

Output pulse frequency for backlash compensation is
0: the set frequency by parameter No. 1853
1: 1/8 of the set frequency.

Backlash compensation method
0: fixed pulse frequency output (set by parameter No. 1853 and
No.1800#6)
1: output according to acceleration/deceleration characteristic

Valid time constant of backlash compensation
acceleration/deceleration

4.9 Spindle Function Adjustment

4.9.1 Spindle Encoder

GSK988T has two-channel encoder input interfaces (CN21 and CN22). CN21 interface is used
for feedback input of spindle speed by default. The selection signal PC2SLC (G28.7) of spindle
encoder in PLC selects the interface through which the feedback pulse is obtained and used for
system control. When encoder interface 2 (CN22) is not connected to a encoder and the selection
signal PC2SLC of position encoder is not set to 1, CN21 is always selected for the feedback input of
spindle speed.

To read the actual spindle speed, relevant parameters and signals should be set correctly.

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Chapter IV Machine Debugging-Functions

Relevant Parameter

No. Bit

3706

3707

3773 Spindle encoder line number (CNT)

3803 The 2nd spindle encoder line number (CNT2)

#1、#0

#1、#0

Gear ratio between spindle encoder and position encoder
00：1 01：2 10：4 11：8

Gear ratio between spindle encoder and the 2
00：1 01：2 10：4 11：8

Meaning

nd

position encoder

4.9.2 Spindle Speed Analog Voltage Control

Spindle speed analog voltage control can be set through CNC parameters. The interface outputs
0~10V analog voltage to control spindle servo drive unit or Inverter. For the 0V~+10V output control,
the CNC calculates the spindle speed through S command and send M code to PLC to determine
the spindle output direction.

Although the S command is for spindle speed, its actual control object is spindle motor.
Therefore, the spindle motor speed and gear are related. In this system, the gear selection signal
(GR1, GR2) determines the current gear on the machine; CNC outputs the spindle speed
corresponding to the gear.

The spindle speed control procedure is shown as follows:

CNC side

S command M command

Machine side

Gear control

G96 G97

Surface speed

S(m/min)

X axis current value

Relevant parameter

When the actual spindle speed is inconsistent with the programmed one, adjust it through
parameter No. 3730, No. 3731. There are two adjust methods according to spindle encoder
connection.

1．The spindle encoder is not used:

Constant surface speed

Motor speed changing

D-A convert

Spindle speed

S(r/min)

Gear selection

GR1 GR2

Spindle motor

Servo spindle

speed control

M

① Set the parameter No. 3730 to 1000 (gain adjustment data of spindle speed analog output) and

parameter No. 3731 to 0 (compensation value of spindle speed analog output offset voltage)

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GSK988T Turning CNC System User Manual (Volume Ⅱ)

before adjustment. Disconnect the CNC and spindle after power-off, and turn on the power again,
then, specify a frequently-used M code (M41-M44) at spindle gear (the default first gear after
power-on).

② In MDI mode, specify S code at the highest speed of current gear. For example, after the first gear

is selected, specify the highest speed of the first gear (parameter No. 3741) and press cycle start
button.

③ Measure the output voltage SVC according to the interface definition in the above section.
④ Set the values in the following formula for parameter No. 3730

value setting

10V

1000

×=

(V) voltage Measured

⑤ After the parameter is set, specify the speed analog output value of the first gear as the spindle

speed of maximum voltage (parameter No. 3741), ensure that the output voltage is 10V.

⑥ Specify S0 in MDI mode.
⑦ Measure the output voltage SVC.

Set the values in the following formula for parameter No. 3731

value setting

=

×

(V) voltage Offset8191-

12.5

Then, specify S0 again and ensure the voltage is 0V.

2．The spindle encoder is used:

① Set the parameter No. 3730 to 1000 (spindle speed analog output gain adjust data) and

parameter No. 3731 to 0 (compensation value of spindle speed analog output offset voltage)
before adjustment. Connect the CNC and spindle after power-off, and turn on the power again,
then, specify a frequently-used M code (M41-M44) at spindle gear (the default first gear after
power-on).

② In MDI mode, specify S code at the highest speed of current gear. For example, after the first

gear is selected, specify the highest speed of the first gear (parameter No. 3741) and press
cycle start button.

③ The actual speed is displayed in position screen, and it should be almost the same with the

specified speed. If the value is too much different from the specified one, please check whether
the encoder parameter setting is correct.

④ Set the values in the following formula for parameter No. 3730

value setting ×=

3741 No. parameter of value Setting

1000

speed rotation Actual

⑤ After the parameter is set, specify the speed analog output value of the first gear as the spindle

speed of maximum voltage (parameter No. 3741), ensure that the actual speed is the value set
by parameter No. 3741.

⑥ Specify S0 in MDI mode.
⑦ Record the actual speed in position screen.
⑧ Input the record actual speed in parameter No. 3731
⑨ Specify command S0 again after the parameter is set, then, ensure that the output speed is 0.

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Chapter IV Machine Debugging-Functions

Relevant Parameter

No. Bit Meaning

3031 Set the permitted digits in S code

When spindle function is used (spindle analog output or spindle serial

3705 #4

3708 #0

3709 #0

3730 Gain adjust data of spindle speed analog output

3731 Compensation value of spindle speed analog output offset voltage

3740 The delay time of spindle speed arrival signal

3741 The maximum spindle speed at gear 1

3742 The maximum spindle speed at gear 2

3743 The maximum spindle speed at gear 3

3744 The maximum spindle speed at gear 4

3772 Upper limit spindle speed (the first spindle)

output), for S command:

0: S code and SF are not output 1: S code and SF are output

Whether check spindle speed arrival signal:

0: No 1: Yes

Sampling frequency for average spindle speed

0: 4 times (usually set to 0) 1: 1 time

4.9.3 Double-Spindle Control

GSK988T has two spindle interfaces for servo spindle control and analog spindle control
respectively. The servo spindle, as the first spindle, can perform contour control in machining; it also
can be used as analog spindle. The analog spindle, as the second spindle, provides the spindle
speed control function.

Before the spindle function is used, the following setting should be made according the actual
machine tool (see section 4.9.2 for relevant setting of the first spindle):

1. Set parameter No. 8133#3 (MSP) to determine whether multi-spindle function (the second

spindle) is used. When the parameter is set to 0, only the first spindle (i.e. servo spindle) is used.

2. Set the maximum speed of two spindles respectively at corresponding gears (the first spindle

has 4 gears, the second spindle has 2 gears); parameter No. 3811, 3812 set the maximum

speed of the second spindle at the 2 gears.

3. Set the upper limit speed of two spindles (the actual speed cannot exceed the upper limit);

parameter No. 3802 sets the upper limit speed of the second spindle.

4. To read the actual speed, parameters related to spindle encoder should be set as follows:

a. the encoder line number: set by parameter No. 3803 (the second spindle)

b. the gear ratio of encoder: set by parameter No. 3707#0, No. 3707#1)

Relevant Parameter

No. Bit

3802 The upper limit speed of the second spindle

3811 Maximum speed of the second spindle at gear 1

3812 Maximum speed of the second spindle at gear 2

8133 #3

Whether the multi-spindle function is used:
0: No 1: Yes

Meaning

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GSK988T Turning CNC system User Manual (Volume Ⅱ)

CHAPTER V PARAMETER INSTRUCTION

This chapter mainly introduces CNC state and data parameters through setting different
parameters to realize the different requirements of function. The parameter data mainly includes the
following four types:

Data Types Range

(1) Bit

(2) Bit axis

(3) Word

(4) Word axis

For the (3) and (4) types, the exact data range is determined by specified parameters.
Each parameter should include the following information:
『Modification Authority』: System authority (1

management authority (3rd level), Operation authority (4th level), Limited authority (5th level)
『Way of Validating』: Become valid immediately or after power-on

8 digits, 0 or 1

-99 999 999～[phone]

st

level), Machine authority (2nd level), Equipment

『Value Range』: In interval, by enumerating or special judgment)
『Default Setting』: 8 digits in binary system, or 32-digit integral value
『Parameter Type』: Bit, bit axis, word, word axis

Note 1: The 『Value Range』of bit type parameters is 0 or 1.
Note 2: When 『Way of Validating』 is not stated, the parameter will become valid

immediately.

Note 3: When 『Parameter Type』 is not stated, the parameter is of bit type or word type.

(1) Bit (axis) type:
Parameter

#7 #6 #5 #4 #3 #2 #1 #0

number

0000 ABCx

『Modification Authority』: System authority
『Way of Validating』: After power-on
『Default Setting』: 0000 0000

#0 ABCx The introduction of the parameter bit (axis) type is:

0: Allowed
1: Forbidden

(2) Word (axis) type:

1000 Parameter name

『Modification Authority』: Equipment management authority
『Way of Validating』: After power-on
『Value Range』: 0～999

Explanation information of parameter in word (axis) type

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Chapter V Parameter Instruction

5.1 Parameters of System Setting

#7 #6 #5 #4 #3 #2 #1 #0

0000 SEQ INI

『Modification Authority』: Equipment management authority
『Default Setting』: 0000 0000

#2 INI Input unit

0: Metric system
1: Inch system

#5 SEQ whether insert the sequence number automatically

0: No
1: Yes

Note: In EDIT or MDI mode, sequence number can be inserted automatically. The

incremental value of sequence number is set in parameter.

5.2 Parameters of the Interfaces of Input and Output

0123 Baud rate of serial port (BPS)

『Modification Authority』:Equipment management
『Value Range』: 4800, 9600, 19200, 38400, 57600, 115200
『Default Setting』: 115200

#7 #6 #5 #4 #3 #2 #1 #0

0138 OWN

『Modification Authority』: Equipment management authority
『Default Setting』: 0000 0000

#6 OWN When NC data or the programs are input or output, whether the covered file
information is displayed:

0: Yes
1: No

5.3 Parameters of Axis Control/Setting Unit

#7 #6 #5 #4 #3 #2 #1 #0

1001 INM

『Way of Validating』: After power-on
『Default Setting』: 0000 0000

#0 INM The least movement increment of linear axis is in:

0: Metric system (metric machine)
1: Inch system (inch machine)

#7 #6 #5 #4 #3 #2 #1 #0

1002 AZR DLZ

『Default Setting』: 0000 0000

#1 DLZ Whether reference setting without dog is valid:

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GSK988T Turning CNC system User Manual (Volume Ⅱ)

0: Invalid
1: Valid (for all axes)

Note: When DLZ is 0, parameter 1005#1 (DLZx) can set valid/invalid for each axis.

#3 AZR G28 command when the reference point is not set:

0: Reference point return with deceleration dog, the same as manual reference point return.
1: P/S alarm occurs

Note: The function of reference point return without dog (when parameter 1002#1

(DLZ) is 1 or parameter 1005#1 (DLZx) is 1) is not related to the setting of AZR. If
G28 is executed before reference point setting, P/S alarm is issued.

#7 #6 #5 #4 #3 #2 #1 #0

1004 RPR ISC

『Way of Validating』: After power-on
『Default Setting』: 0000 0000

#1 ISC Set the least input increment and least command increment

ISC Least input unit, least command increment Abbreviation

0 0.001mm, 0.001deg or 0.0001inch IS-B

1 0.0001mm, 0.0001deg or 0.00001inch IS-C

#6 RPR Whether set the minimum input unit of the rotary axis as 10 times of the
minimum command increment

0: Not set it as 10 times

1: Set as it 10 times

#7 #6 #5 #4 #3 #2 #1 #0

1005 HJZx DLZx ZRNx

『Parameter Type』: Bit axis
『Default Setting』: 0000 1000

#0 ZRNx Whether the system alarms if the other traverse commands are specified

except G28 before setting the reference point in auto running (MEM, DNC or MDI).

0: Alarm

1: Not alarm

#1 DLZx Whether setting the reference point free of the link stopper is valid.

0: Invalid
1: Valid

Note: Parameter DLZ (No.1002#1) is valid when it is “0”. When DLZ (No.1002#1) is

“1”, there is no connection with the parameter, and setting the reference
point free of the link stopper is valid for all axes.

#3 HJZx After the reference point is set, manually return to the reference point.

0: Use the deceleration link stopper to return to the reference point
1: No connection with the deceleration link stopper, rapidly position in the reference point.

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Chapter V Parameter Instruction

#7 #6 #5 #4 #3 #2 #1 #0

1006 ZMIx DIAx ROSx ROTx

『Way of Validating』: After power-on
『Parameter Type』: Bit axis
『Default Setting』: 0000 0000

#0, #1 ROTx, ROSx set linear axis or rotary axis

ROSx ROTx Content

Linear axis

0 0

0 1

1 0 Invalid setting

1 1

#3 DIAx sets the traverse amount of each axis

0: specified by the radius
1: specified by the diameter

#5 ZMIx sets the direction of each axis reference point return

0: positive direction
1: negative direction

#7 #6 #5 #4 #3 #2 #1 #0

1008 RRLx RABx ROAx

『Way of Validating』: After power-on

Metric/inch conversion
All coordinate values are of the linear axis type.
The stored pitch error compensation is of the linear axis type.

Rotary axis (type A)
No metric/inch conversion
The machine coordinate value displays in 0～360° cycle.

The stored pitch error compensation is of the rotary axis type.
Automatically return to the reference point at the direction of the reference
point return (G28 and G30), the traverse amount can not exceed one turn.

Rotary axis (type B)
No metric/inch conversion
The machine coordinate value, the relative coordinate value and the
absolute coordinate value are in the linear axis, which can't display in cycle
of 0～360°.

The stored pitch error compensation is of the linear axis type.
The cycle function and the indexing function of the rotary axis can not be
used at the same time.

『Parameter Type』: Bit axis
『Default Setting』: 0000 0000

#0 ROAx sets whether the cycle display function of the rotary axis valid.

0: Invalid
1: Valid

Note: ROAx is just valid for the rotary axis and parameter ROTx (No.1006#0) must be 1.

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GSK988T Turning CNC system User Manual (Volume Ⅱ)

#1 RABx sets the rotation direction of the axis during the absolute command.

0: Rotation direction close to the target
1: Direction specified by the command value coder

Note: RABx is valid only when parameter ROAx is 1.

#2 RRLx Relative coordinate

0: Not cycle as the movement amount of each turn

1: Cycle as the movement amount of each turn

Note1: RRLx is valid only when ROAx is 1.
Note2: The movement amount of each turn is set by parameter No.1260.

1010 Quantity of CNC controlled axes (CCA)

『Way of Validating』: After power-on
『Data Range』：0～total number

Set the total number of axes which is directly controlled by CNC, the other can be controlled by PLC.

#7 #6 #5 #4 #3 #2 #1 #0

1015 DWT WIC

『Modification Authority』: Equipment management authority
『Default Setting』: 0000 0000

#6 WIC The offset measured value of the work piece origin is directly input

0: Only valid for the selected work piece coordinate system
1: Valid for all coordinate systems

#7 DWT When the pause time is specified by P, the data units are

0: IS-B is 1ms, IS-C is 0.1ms.
1: 1 ms

1020 Programming name of each axis (CAN)

『Parameter Type』: Word axis
『Value Range』: 88(X), 89(Y), 90(Z), 65(A), 66(B), 67(C)

Set the axial name of each controlled axis.

Note: The same axial name can not be set. The address used by the 2nd miscellaneous

function can not be taken as the axial name.

1022 The property of each axis in the basic coordinate system

『Way of Validating』: After power-on
『Parameter Type』: Word axis
『Value Range』: 0～7

To ensure the planes of the arc interpolation, the tool offset and the tool nose radius, etc.
G17: X－Y plane

G18: Z－X plane
G19: Y－Z plane

Set each controlled axis as one of three basic axes---X, Y and Z axes in the basic

coordinate system, or the parallel axis which is paralleled with these axes. Only one axis of

88

Chapter V Parameter Instruction

the basic three axes can be set: X, Y and Z; the parallel axes can be set as two more axes
(which is paralleled with the basic axis).

Setting value Meaning

0 They are neither basic three axes nor the parallel axes,

1 X axis of the basic three axes

2 Y axis of the basic three axes

3 Z axis of the basic three axes

5 Parallel axis of X axis

6 Parallel axis of Y axis

7 Parallel axis of Z axis

1023 Servo axis number of each axis (NSA)

『Way of Validating』: After power-on
『Value Range』: 1～quantity of controlled axes
『Parameter Type』: Word axis

th

Set each controlled axis as the corresponding N
control axial number and that of the servo axial number are same. The so-called controlled axis
number is to set parameter in the axis or the serial number of the signal in the axis. When the spindle
is taken as the controlled axis, it is set as 5.

servo axis. Generally, the setting value of the

5.4 Parameters of the Coordinate System

#7 #6 #5 #4 #3 #2 #1 #0

1201 WZR ZCL

『Modification Authority』: Equipment management authority
『Default Setting』: 0000 0000

#2 ZCL After manually return to reference point, the part coordinate system

0: Not cancel
1: Cancel

#7 WZR Work piece coordinate system during resetting

0: Not return to G54
1: Return to G54

#7 #6 #5 #4 #3 #2 #1 #0

1202 RLC G50 EWS EWD

『Modification Authority』: Equipment management authority
『Default Setting』: 0000 0000

#0 EWD The movement direction of the coordinate system caused by the external work
piece origin offset amount

0: It is same as the direction specified by the external work piece origin offset amount.
1: It is opposite to the direction specified by the external work piece origin offset amount.

#1 EWS The work piece coordinate system movement amount and the external work
piece zero point offset amount

0: Saved in each memorizer
1: Saved in one memorizer (the work piece coordinate system movement amount is same as

89