Delta Tau 5xx-603869-xUxx manual Setting up Quadrature Encoders, Signal Format, Hardware Setup

Page 32

Brick Motion Controller Hardware Reference Manual

Setting up Quadrature Encoders

Digital quadrature encoders are the most common position sensors used with Geo Drives. Interface circuitry for these encoders comes standard on board-level Turbo PMAC controllers, UMAC axis- interface boards, Geo drives, and QMAC control boxes.

Signal Format

Quadrature encoders provide two digital signals that are a function of the position of the encoder, each nominally with 50% duty cycle, and nominally one-quarter cycle apart. This format provides four distinct states per cycle of the signal, or per line of the encoder. The phase difference of the two signals permits the decoding electronics to discern the direction of travel, which would not be possible with a single signal.

Typically, these signals are at 5V TTL/CMOS levels, whether single-ended or differential. The input circuits are powered by the main 5V supply for the controller, but they can accept up to +/-12V between the signals of each differential pair, and +/-12V between a signal and the GND voltage reference.

Differential encoder signals can enhance noise immunity by providing common-mode noise rejection. Modern design standards virtually mandate their use for industrial systems, especially in the presence of PWM power amplifiers, which generate a great deal of electromagnetic interference.

Hardware Setup

The Geo Drive accepts inputs from up to eight digital encoders and provides encoder position data to the motion processor. X1 is encoder 1 connector and X2 is encoder 2 and respectively up to X8. The differential format provides a means of using twisted pair wiring that allows for better noise immunity when wired into machinery.

Geo Drives encoder interface circuitry employs differential line receivers. The wiring diagram on the right shows an example of how to connect the Geo drive to a quadrature encoder.

Function	Pin #
CHAn+	1
CHAn-	9
CHBn+	2
CHBn-	10
CHCn+	3
CHCn-	11
ENCPWR	4
GND	12

1 CHAn+

9 CHAn-

2 CHBn+

10 CHBn-

3 CHCn+

11 CHCn-

4 ENCPWRn

	12	GND
	5	Shield
	13	Shield
	13
	6
	14
	7
	15
	8

	Encoder Decode	Value	Description
	I7mn0	3	Clockwise decode
	I7mn0	7	Counter clockwise decode
		7	Counter clockwise decode

m = 0 for axis 1-4 (n = 1-4) and m = 1 for axis 5 – 8 (n = 1-4)

24	System Wiring

Image 32

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