Iai-america MSCON Manual de usuario

MSCON Controller Instruction Manual First Edition

2No.OperationDescription Description 2 Transportation Ɣ When carrying a heavy object, do the work with two or more persons or utilize equipment such

3.4 Fieldbus Type Address Map92(ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Contents Details b15 RUN This sig

3.4 Fieldbus Type Address Map933.4.4 Control Signals for Direct Simple Direct To select the mode, use Gateway Parameter Setting Tool. This is the ope

3.4 Fieldbus Type Address Map94(2) Input and Output Signal Assignment for each Axis The I/O signals for each axis consists of 4 words for each I/O bi

3.4 Fieldbus Type Address Map95PLC Input (m is PLC input top word address for each axis number). 䎃䎃Address m b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b

3.4 Fieldbus Type Address Map96(3) I/O signal assignment (ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Contents

3.4 Fieldbus Type Address Map97(ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Contents Details CurrentPosition32

3.4 Fieldbus Type Address Map983.4.5 Control Signals for Positioner 1 Mode To select the mode, use Gateway Parameter Setting Tool. This is the method

3.4 Fieldbus Type Address Map99(2) Input and Output Signal Assignment for each Axis The I/O signals for each axis consists of 4 words for each I/O bi

3.4 Fieldbus Type Address Map100PLC Input (m is PLC input top word address for each axis number). 䎃䎃Address m b15 b14 b13 b12 b11 b10 b9 b8 b7 b6

3.4 Fieldbus Type Address Map101(3) I/O signal assignment (ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Contents

3No.OperationDescription Description (2) Cable Wiring Ɣ Use our company’s genuine cables for connecting between the actuator and controller, and for

3.4 Fieldbus Type Address Map102(ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Contents Details CurrentPosition3

3.4 Fieldbus Type Address Map1033.4.6 Control Signals for Direct Indication Mode This is an operation mode to indicate directly with values for the t

3.4 Fieldbus Type Address Map104(2) I/O Signal Allocation for each Axis The I/O signals for each axis consists of 8 words for each I/O bit register.

3.4 Fieldbus Type Address Map105PLC Output (m is PLC output top word address for each axis number) Address m b15 b14 b13 b12 b11 b10 b9 b8 b7 b6

3.4 Fieldbus Type Address Map106PLC Input (m is PLC input top word address for each axis number).䎃䎃Address mb15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b

3.4 Fieldbus Type Address Map107(3) I/O signal assignment (ON = Applicable bit is “1”, OFF = Applicable bit is “0”) Signal Type Bit Symbol Contents

3.4 Fieldbus Type Address Map108Signal Type Bit Symbol Contents Details b15 BKRLBrake release ON: Brake release, OFF: Brake activated 3.7 (17)b14

3.4 Fieldbus Type Address Map109(ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Contents Details CurrentPosition3

3.4 Fieldbus Type Address Map110 3.4.7 Control Signals for Direct Indication Mode 2 This is an operation mode to indicate directly with values for t

3.4 Fieldbus Type Address Map111 (2) I/O Signal Allocation for each Axis The I/O signals for each axis consists of 8 words for each I/O bit register.

4No.OperationDescription Description 4 Installation and Start (4) Safety Measures Ɣ When the work is carried out with 2 or more persons, make it cle

3.4 Fieldbus Type Address Map112 PLC Output (m is PLC output top word address for each axis number) Address m b15 b14 b13 b12 b11 b10 b9 b8 b7 b

3.4 Fieldbus Type Address Map113 PLC Input (m is PLC input top word address for each axis number).䎃䎃Address mb15 b14 b13 b12 b11 b10 b9 b8 b7 b6

3.4 Fieldbus Type Address Map114 (3) I/O signal assignment (ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Content

3.4 Fieldbus Type Address Map115 Signal Type Bit Symbol Contents Details b15 BKRLBrake release ON: Brake release, OFF: Brake activated 3.7 (17)b14

3.4 Fieldbus Type Address Map116 (ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Contents Details CurrentPosition

3.4 Fieldbus Type Address Map117 3.4.8 Control Signals for Positioner 2 Mode This is the operation mode with the position No. set up. The operation i

3.4 Fieldbus Type Address Map118 (2) Input and Output Signal Assignment for each Axis The I/O signals for each axis consists of 2 words for each I/O

3.4 Fieldbus Type Address Map119 (3) I/O signal assignment (ON = Applicable bit is “1”, OFF = Applicable bit is “0”) Signal Type Bit Symbol Conten

3.4 Fieldbus Type Address Map120(ON = Applicable bit is “1”, OFF = Applicable bit is “0”) Signal Type Bit Symbol Contents Details Completed Positi

3.4 Fieldbus Type Address Map1213.4.9 Control Signals for Positioner 3 Mode This is the operation mode with the position No. set up. The operation is

5No.OperationDescription Description 6 Trial OperationƔ When the work is carried out with 2 or more persons, make it clear who is to be the leader a

3.4 Fieldbus Type Address Map122(2) Input and Output Signal Assignment for each Axis The I/O signals for each axis consists of 1 words for each I/O b

3.4 Fieldbus Type Address Map123(3) I/O signal assignment (ON = Applicable bit is “1”, OFF = Applicable bit is “0”)Signal Type Bit Symbol Content

3.4 Fieldbus Type Address Map1243.4.10 Control Signals for Remote I/O Mode It is an operation mode to control with ON/OFF of bits as it is done in PI

3.4 Fieldbus Type Address Map125(1) PLC Address Composition (m is PLC input and output top word address for each axis number)PLCĺMSCON (PLC Output)

3.4 Fieldbus Type Address Map126(3) I/O signal assignment The controller's I/O port signal varies depending on the parameter No.25 setting. [Ref

3.4 Fieldbus Type Address Map127Set the parameter No.25 of MSCONSolenoid valve mode 1 Solenoid valve mode 2 4 5 Category PortNo.Symbol Signal Name S

3.4 Fieldbus Type Address Map1283.4.11 About Commands (Position Data Read/Write and Alarm Axis Read) By sending a specific code to a specific address

3.4 Fieldbus Type Address Map129(3) Details of Commands The input and output signals are consist of 5 words for each input and output data register.

3.4 Fieldbus Type Address Map1301) Demand command cleared PLC Output (Address n is the input and output top address for MSCON Gateway Unit.) (Note) R

3.4 Fieldbus Type Address Map1313) Writing of Positioning Width PLC Output (Address n is the input and output top address for MSCON Gateway Unit.) (N

6No.OperationDescription Description 8 Maintenance andInspection Ɣ When the work is carried out with 2 or more persons, make it clear who is to be t

3.4 Fieldbus Type Address Map1325) Writing of Acceleration PLC Output (Address n is the input and output top address for MSCON Gateway Unit.) (Note)

3.4 Fieldbus Type Address Map1337) Writing of Pressing Current Limit PLC Output (Address n is the input and output top address for MSCON Gateway Unit

3.4 Fieldbus Type Address Map1348) Reading of Target Position PLC Output (Address n is the input and output top address for MSCON Gateway Unit.)  B

3.4 Fieldbus Type Address Map1359) Reading of Pressing Width PLC Output (Address n is the input and output top address for MSCON Gateway Unit.)  Bi

3.4 Fieldbus Type Address Map13610) Reading of Speed PLC Output (Address n is the input and output top address for MSCON Gateway Unit.)  Bit Addres

3.4 Fieldbus Type Address Map13711) Reading of Acceleration PLC Output (Address n is the input and output top address for MSCON Gateway Unit.)  Bit

3.4 Fieldbus Type Address Map13812) Reading of Deceleration PLC Output (Address n is the input and output top address for MSCON Gateway Unit.) Bit

3.4 Fieldbus Type Address Map13913) Reading of Pressing Current Limit PLC Output (Address n is the input and output top address for MSCON Gateway Uni

3.4 Fieldbus Type Address Map14014) Reading of Alarm-issued Axis Number PLC Output (Address n is the input and output top address for MSCON Gateway U

3.4 Fieldbus Type Address Map14115) Reading of Alarm Code PLC Output (Address n is the input and output top address for MSCON Gateway Unit.) (Note) I

7Alert Indication The safety precautions are divided into “Danger”, “Warning”, “Caution” and “Notice” according to the warning level, as follows, and

3.4 Fieldbus Type Address Map14216) Error Response Command PLC Output (Address n is the input and output top address for MSCON Gateway Unit.) In the

3.5 Control Signals for PIO Operation1433.5 Input and Output Signal Process for Field Network (1) I/O Signal Timings When any of the control signal

3.5 Control Signals for PIO Operation144(2) Command Sending and Receiving Timing (Reading and Writing of Position Data and Reading of Alarm Axis) By w

3.6 Power Supply and Cutoff1453.6 Power Supply and Cutoff (1) Timing for Supplying Power Turn ON the control power and motor driving source at the s

3.6 Power Supply and Cutoff146(3) Power supply status LED The conditions of the control power and motor driving source can be checked on the power su

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff1473.7 Control and functions of Inp

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff148(5) Servo ON command (SON) PLC

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff149(6) Home return (HOME) PLC Outp

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff150[Operation of Slider Type/Rod Typ

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff151[For Gripper Type] 1) If the HOME

8Precautions in Operation 1. Make sure to follow the usage condition, environment and specification range of the product. Not doing so may cause a dr

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff152(7) Positioning start (CSTR) PL

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff153Caution: When the servo-motor is

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff154(2) Position zone signal (PZONE)

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff155(10) + Jog (JOG+) PLC Output Sign

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff156(11) Jog-speed/inch-distance swi

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff157(13) Teaching mode command (MODE)

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff158(15) Brake release (BKRL) PLC Out

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff159(17) Push direction specification

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff160(20) Warning for Absolute Batte

3.7 Control and functions of Input and output signals of Modes other than Remote I/O Mode Power Supply and Cutoff161(22) Acceleration/deceleration m

97. For the rotary actuator, it is necessary to pay attention to cable breakage due to twisting and other factors. Especially for the type with a thr

10Also, if one tries to read the signal that is being re-written by the other, the signal may be read wrongly. Make sure to read the signal after the

11 International Standards Compliances MSCON comply with the following overseas standards. RoHS Directive CE Marking UL٤To be scheduled Compliance

12

13Name for Each Parts and Their Functions No.0No.1No.2No.3No.4No.516) Absolute Battery Unit 1) Control power supply input connector 3) Regenerative re

141) Control power supply input connector [Refer to 2.2 [2] Power Supply Circuit and Brake Circuit] Supply 24V DC power for control. For an actuator

157) Actuator driver for Axis No.0 and No.1 8) Actuator driver for Axis No.2 and No.3 9) Actuator driver for Axis No.4 and No.5 One piece of a driv

1610) Operation mode setting switch This is a switch to change the operation mode between Automatic Operation (AUTO) and Manual Operation (MANU). The

17Actuator Axes Refer to the pictures below for the actuator axes that can be controlled.0 defines the home position, and items in ( ) are for the hom

18300°0°-+-+(5) Gripper Type (6) Rotary Type (300q Rotation Specification) (360qRotation Specification) (360qRotation Specification) For Multiple R

19Starting Procedures When using this product for the first time, work while making sure to avoid omission and incorrect wiring by referring to the pr

20

Chapter 1 Specications Check21Chapter 1 Specifications Check 1.1 Product Check 1.1.1 Parts The standard configuration of this product is comprised

[Important] x This Instruction Manual is original. x The product cannot be operated in any way unless expressly specified in this Instruction Manual

Chapter 1 Specications Check221.1.3 Instruction Manuals related to this product, which are contained in the DVD. No. Name Manual No.1 MSCON Contr

Chapter 1 Specications Check231.1.5 How to read the model (Example) Consists of 5 axes : Axis No.0, 2, 3 : 60W actuators to be connected Axis No

Chapter 1 Specications Check241.2 Basic Specifications Number of Controlled Axes Max. 6-axis Control Power Voltage 24V DC r10% Control Power Curre

Chapter 1 Specications Check25Withstanding Voltage (Between primary and secondary power sources, Between primary power source and PE) 1500V AC for 1

Chapter 1 Specications Check261.3 Selection of Power Source and Power Supply Supportive Devices 1.3.1 Power Capacity and Heat Generation Shown in t

Chapter 1 Specications Check271.3.3 Selection of Leak Current Breaker • It may be mandatory by law to install a leakage breaker. • A ground fault

Chapter 1 Specications Check281.4 Specifications for each Fieldbus 1.4.1 Specifications of DeviceNet Interface Item Specification DeviceNet2.0Grou

Chapter 1 Specications Check291.4.3 Specifications of PROFIBUS-DP Interface Item Specification CommunicationProtocolPROFIBUS-DP Baud Rate Automati

Chapter 1 Specications Check301.4.5 Specifications of MECHATROLINK II Interface Item Specification Slave Type Intelligent I/O Baud Rate MECHATROL

Chapter 1 Specications Check311.5 External Dimensions 1.5.1 Incremental Type 1022042251029913610.510.510.510.551541454.54.545(9)3-φ5Front View 10

Chapter 1 Specications Check321.5.2 Absolute Type 1022042251029913610.510.510.510.551541454.54.545(9)(22.3)3-φ5Front View 10.511510.5(77 from DIN ra

Chapter 1 Specications Check331.6 Option 1.6.1 Regenerative Resistor Unit This unit is necessary to be connected in the case that the regenerative

Chapter 1 Specications Check34[RESU-*Type External Dimensions: Screw Attachment Type] 16.8517.1530.734106.54.51.5φ51.554.5R2.5145154136[RESUD-*Type E

Chapter 1 Specications Check351.7 Installation and Storage Environment This product is capable for use in the environment of pollution degree 2*1 or

Chapter 1 Specications Check361.8 Noise Elimination and Mounting Method (1) Noise Elimination Grounding (Frame Ground) (2) Precautions regarding

Chapter 1 Specications Check37(4) Heat Radiation and Installation Design and Build the system considering the size of the controller box, location o

Chapter 1 Specications Check38

Chapter 2 Wiring39Chapter 2 Wiring 2.1 Wiring Diagram (Connection of construction devices) Teaching Pendant Touch Panel Teaching (to be purchased se

Chapter 2 Wiring402.2 Circuit Diagram Sample circuit diagrams are shown below. [1] Drive (Motor) Power Supply Circuit Note: Drive power supply volt

Chapter 2 Wiring41[3] Emergency Stop Circuit It is the example of circuit layout when an emergency switch of the teaching pendant is used to the emer

Contents Safety Guide ·····················································································································1 Precautio

Chapter 2 Wiring42[4] Motor • Encoder Circuit MSCON Note 1: Applicable Moter Cable types ƑƑƑ: cable length Example) 030 = 3m Model Name C

Chapter 2 Wiring43[6] Regenerative Resistance Circuit MSCON [7] Mode Switchover (AUTO/MANU) Circuit When a switchover of the operation

Chapter 2 Wiring44[8] Field Network Circuit (For Field Network Type) Refer to the instruction manual of the master unit for each field network and co

Chapter 2 Wiring454) CompoNet Type BS+BDLBDHBS-BS+BDLBDHBS-BS+BDLBDHBS-Master Unit Slave DeviceTerminal Resistance121ΩMSCONCompoNet TypeConnect the te

Chapter 2 Wiring466) MECHATROLINK Type 432143214321A4A3A2A1B4B3B2B1Master Unit Slave DeviceMECHATROLINKCableMECHATROLINK CableMSCONMECHATROLINK TypeTe

Chapter 2 Wiring472.3 Wiring Method 2.3.1 Wiring of Control Power Supply and Drive Power Supply Input Connector Insert the wires to the enclosed con

Chapter 2 Wiring48(2) Drive (Motor) Power Supply Input Connector 㩷㩷㩷Power Supply Input Connector Model Remarks Cable Side MC2.5/3-STF-7.62 Enclose

Chapter 2 Wiring492.3.2 Wiring Layout of System I/O Connector This consists of the emergency stop input and cable terminals for the operation mode (A

Chapter 2 Wiring502.3.3 Actuator Connection To the encoder connector and motor connector on each actuator, connect the relay cables. [Refer to the No

Chapter 2 Wiring51(2) Motor Connector 㩷㩷㩷Motor Connector Model Remarks Cable Side GIC2.5/4-STF-7.62 Controller Side GIC2.5/4-GF-7.62 Pin No.

Chapter 3 Operation ·······································································································61 3.1 Basic Operation ···

Chapter 2 Wiring522.3.4 Battery Connection (For Absolute Type) If the actuator is the absolute type, connect the harness of the absolute battery unit

Chapter 2 Wiring532.3.5 Connection of Regenerative Resistance Unit Connect the regenerative resistance unit with a cable enclosed with it referring t

Chapter 2 Wiring54Connection Cable 1) Regenerative resistance connection cable for SCON (CB-SC-REU010) Cable length : 1m Regenerative Resistor

Chapter 2 Wiring552.3.6 Connection of SIO Connector Connect an applicable teaching tool such as the PC software. 㩷SIO connector Model Remarks Cable

Chapter 2 Wiring562.3.7 Wiring Layout of Field Network Connector Check the instruction manuals for each Field Network master unit and mounted PLC

Chapter 2 Wiring572) CC-Link Type WT (DB)BL (DA)Shield (SLD)YW (DG)㩷CC-Link Connector Model Remarks Cable Side SMSTB2.5/5-ST-5.08 AU Enclosed in s

Chapter 2 Wiring583) PROFIBUS-DP Type 5 19 6CableShieldRed B line (Positive side)Use the type A cable for PROFIBUS-DP (EN5017

Chapter 2 Wiring594) CompoNet Type 㩷㩷CompoNet Connector Model Remarks Cable Side Connector that complies with CompoNet standards Please prepare separ

Chapter 2 Wiring606) MECHATROLINK Type 㩷MECHATROLINK Connector Model Remarks Cable Side Connector that complies with MECHATROLINK standards Controll

Chapter 3 Operation61Chapter 3 Operation 3.1 Basic Operation 3.1.1 Basic Operation Methods This controller is to be controlled with fieldbus. Even

Chapter 6 Absolute Reset and Absolute Battery ··························································241 6.1 Absolute Reset·······················

3.1 Basic Operation62[Basic Operation Procedures] [1] Establish the parameter settings on all the connected axes by using a teaching tool such as the

3.1 Basic Operation63Ɣ Operation Mode Available 7 types of operation modes are available to select from. The settings are to be established with Gate

3.1 Basic Operation64Operation PatternContents Overview Remote I/O Five types (Note 1) of control same for PIO are available.Note : It is to be sw

3.1 Basic Operation653.1.2 Parameter Settings Parameter data should be set appropriately according to the applicaiton requirements. Parameters are va

3.2 Initial Setting663.2 Initial Setting The operation mode is to be set using Gateway Parameter Setting Tool (Ver. 1.2.0.0 or later). Registration o

3.2 Initial Setting67 [Step 4] The main window opens. The main window opens even when MSCON could not be detected. Main windows (Initial condition)

3.2 Initial Setting68[Step 6] The parameters input to MSCON are listed as shown below. Indicate the Field Network node addresses in Address. Caution

3.2 Initial Setting69[Step 8] Select an operation mode for each drive unit (in 2 axes unit). Select an operation mode for Drive Unit 0 (AX0: 1st ax

3.2 Initial Setting70[Step 13] Write the edited operation mode setting parameters to MSCON. Click on the “Transfer” button shown below and a confirma

3.3 Setting of Position Data713.3 Setting of Position Data The values in the position table can be set as shown below. In the case that only position

3.3 Setting of Position Data723) Velocity [mm/s]···· Set the velocity in the operation. Do not attempt to input a value more than the maximum veloci

3.3 Setting of Position Data738) Positioning width [mm] ··In Positioner * Mode, Simple Direct Mode and PIO patterns*1 0 to 2 and 4 in Remote I/O Mod

3.3 Setting of Position Data7410) Zone - [mm] (Note) ·········· Set the coordinate value on the negative side at which position zone output signal PZ

3.3 Setting of Position Data7512) Incremental········· Set to 1 for pitch feed (relative movement = incremental feed). The value set for the position

3.3 Setting of Position Data76  Caution: y No retaining torque is provided in automatic servo OFF. Pay sufficient attention to the setting because

3.4 Fieldbus Type Address Map773.4 Fieldbus Type Address Map 3.4.1 PLC Address Construction by each Operation Mode The address domain to be occupied

3.4 Fieldbus Type Address Map78Note1: For CC-Link, n and n+1 are for input and output bit addresses, and n+8 is for the top address of data register.

3.4 Fieldbus Type Address Map79y MSCON Output ĺ PLC Input (n is PLC input top word address from MSCON)(Note 1)PLCInput Area SimpleDirectModePositioner

3.4 Fieldbus Type Address Map803.4.2 Example for Address Map Construction for each Field Network Shown below is an example for the address map by the

3.4 Fieldbus Type Address Map81[Combination Example 2] When number of Simple Direct Mode axes is 4 (axis No.0 to No.3) and number of Direct Indication

1Safety Guide “Safety Guide” has been written to use the machine safely and so prevent personal injury or property damage beforehand. Make sure to rea

3.4 Fieldbus Type Address Map822) CC-Link [Combination Example 1] When number of Simple Direct Mode axes is 6 and number of Direct Indication Mode 0 (

3.4 Fieldbus Type Address Map83[Combination Example 3] When number of Simple Direct Mode axes is 0 and number of Direct Indication Mode 6 (Extended Cy

3.4 Fieldbus Type Address Map84[Combination Example 2] When number of Simple Direct Mode axes is 4 (axis No.0 to No.3) and number of Direct Indication

3.4 Fieldbus Type Address Map85[2] Address Map for Positioner 2 Mode Shown below is the address map for each Field network when six axes of MSCON are

3.4 Fieldbus Type Address Map863) PROFIBUS-DP, EtherNet/IP, EtherCAT (MECHATROLINK is not applicable for this mode) (n is the top node address for eac

3.4 Fieldbus Type Address Map872) CC-Link (Extended Cyclic Setting/Number of Occupied Stations: 1 times/4 stations) PLCĺMSCON MSCONĺPLCAddress Cont

3.4 Fieldbus Type Address Map88[4] Address Maps in Remote I/O Mode Shown below are the address maps when operation of 6-axis MSCON is made with Remot

3.4 Fieldbus Type Address Map893) PROFIBUS-DP, EtherNet/IP, MECHATROLINK, EtherCAT (n is the top node address for each PLC input and output between MS

3.4 Fieldbus Type Address Map903.4.3 Gateway Control Signals (in common for all operation modes) When operating the system with Fieldbus, the axes ar

3.4 Fieldbus Type Address Map91(2) List for Input and Output Signal (ON = Applicable bit is “1”, OFF = Applicable bit is “0”) Signal Type Bit Symbo