Delta Tau 5xx-603869-xUxx manual Type of Cable for Encoder Wiring

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Brick Motion Controller Hardware Reference Manual

Type of Cable for Encoder Wiring

Low capacitance shielded twisted pair cable is ideal for wiring differential encoders. The better the shield wires, the better the noise immunity to the external equipment wiring. Wiring practice for shielded cables is not an exact science. Different applications will present different sources of noise, and experimentation may be required to achieve the desired results. Therefore, the following recommendations are based upon some experiences that we at Delta Tau Data Systems have acquired.

If possible, the best cabling to use is a double-shielded twisted pair cable. Typically, there are four pairs used in a differential encoder’s wiring. The picture below shows how the wiring may be implemented for a typical differential sinusoidal encoder using double shielded twisted pair cable.

SIN+

SIN-

SHIELD

COS+

COS-

SHIELD

INDEX+

INDEX-

SHIELD

ENC PWR

GND

SHIELD

OUTER

SHIELD

EXAMPLE OF DOUBLE SHIELDED

4 TWISTED PAIR CABLE

The shield wires should be tied to ground (Vcc return) at the interpolator end. It is acceptable to tie the shield wires together if there are not enough terminals available. Keep the exposed wire lengths as close as possible to the terminals on the interpolator.

Note:

It has been observed that there is an inconsistency in the shielding styles that are used by different encoder manufacturers.

Be sure to check pre-wired encoders to ensure that the shield wires are not connected at the encoder’s side. Shield wires should be connected only on one side of the cable.

If the encoder has shield wires that are connected to the case ground of the encoder, ensure that the encoder and motor cases are sufficiently grounded. Do not connect the shield at the interpolator end.

If the encoder has pre-wired double shielded cable that has only the outer shield connected at the encoder, then connect only the inner shield wires to the interpolator. Be sure not to mix the shield interconnections.

One possible cable type for encoders is Belden 8164 or ALPHA 6318. This is a 4-pair individually shielded cable that has an overall shield. This double-shielded cable has a relatively low capacitance and is a 100Ω impedance cable.

Cables for single-ended encoders should be shielded for the best noise immunity. Single-ended encoder types cannot take advantage of the differential noise immunity that comes with twisted pair cables.

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Appendix A

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Contents 125 Safety Instructions Copyright InformationOperating Conditions Delta Tau Data Systems, Inc. Technical SupportPage Page Revision History Page Table of Contents Brick Motion Controller Hardware Reference Manual Brick Motion Controller Features IntroductionBrick Motion Controller Hardware Reference Manual Part Number Brick Motion Controller OptionsMacro and Special Feedback Options Analog I/O OptionsCommunication Options Receiving and Unpacking Use of EquipmentBrick Motion Controller Hardware Reference Manual Earth Grounding Paths Wiring Earth-GroundNoise Problems X1-X8 Encoder Input 1 to ConnectorsPin Symbol Function X9/10 Female DB-9 Connector Pin # Symbol X11/12 Female DB-9 Connector Pin # Symbol FunctionX9-10 Analog I/O Ch5 X9 and Ch6 X10, Optional X11-12 Analog I/O Ch7 X11 and Ch8 X12, OptionalX13 USB 2.0 Connector X14 RJ45, Ethernet ConnectorPin # Symbol X15 WatchdogS2 Firmware Reload Enable TB1 Power ConnectorS1 Re-Initialization on Reset Control J4 Limit Inputs 1-4 Axis DescriptionLimit and Flag Circuit Wiring J5 Limit Inputs 5-8 AxisSample J4/J5, Flags Wiring Diagrams GNDAMP1-AMP8 Amplifier connections 1 to Amplifier Fault / Amplifier Enable diagrams J6 General Purpose I/O Female DB-37 Connector Pin # Symbol J6 General Purpose I/OSuggested M-var. # Address Sourcing SinkingSymbol Function J7 Extra General Purpose I/O OptionalSuggested M-var. # Address J8 General Purpose I/O Female DB-37 Connector Pin # Symbol J8 Extra General Purpose I/O OptionalSuggested M-var. # Address Sample J6/J7, I/O Wiring Diagrams GBLSetting up Quadrature Encoders Signal FormatHardware Setup Function Pin #Encoder Loss Setup Channel# Address DescriptionBipolar Setting up the Analog Inputs optionalFiltered DAC Outputs Configuration optional Parameters to Set up Global Hardware Signals Parameters to Set Up Per-Channel Hardware Signals Setting up for Pulse and Direction Output Software SetupI7m00 Servo IC m MaxPhase/PWM Frequency Control Multi-Channel Servo IC I-VariablesI7mn6 Servo IC m Channel n Output Mode Select Single-Channel I-VariablesI7m04 PFM Pulse Width Control I7mn0 Servo IC m Channel n Encoder Decode ControlIxx34 Motor xx Integration Mode Ixx30 Motor xx Proportional GainExample Ixx31 Motor x Derivative GainBrick Motion Controller Hardware Reference Manual Diagnosing Cause of Watchdog Timer Trip Watchdog TimerActions on Watchdog Timer Trip Troubleshooting DB- Connector Spacing Specifications X1-8 DB-15 Connectors for encoder feedbackX9-12 DB-9 Connectors for Analog I/O Screw Lock Size for all DB-connectorsType of Cable for Encoder Wiring Appendix a Inputs SchematicsJ6 and J7 General Purpose I/O Opto Gnd Plane OutputsJ4 Limit Inputs for Axis Limits 1,2,3,4J5 Limit Inputs for Axis Limits 5,6,7,8Dimensional Layout and Connector location
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