Moons' SRAC2 User manual

SRAC2
AC Input Step Motor Drive
User Manual
Rev. 1.1
AMP & MOONS’ Automation

2
Rev. 1.2
10/6/2021
SRAC2 User Manual
Contents
1 Introduction.................................................................................. 3
1.1 Features.............................................................................................3
1.2 Block diagram ....................................................................................4
2 Mounting the Drive ...................................................................... 4
3 Connections ................................................................................ 5
3.1 Connecting to Power .........................................................................6
3.3 Connecting the Inputs and Outputs ...................................................8
3.3.1 Step & Direction Inputs..............................................................................8
3.3.2 EN input.....................................................................................................9
3.3.3 Fault Output.............................................................................................10
4 Switch Selection ........................................................................ 11
4.1 Microstep Resolution ....................................................................... 11
4.2 Running Current ..............................................................................12
4.3 Idle Current ......................................................................................12
4.4 Step Input Signal Filter ....................................................................12
4.5 Anti Resonance................................................................................12
4.6 Step Smoothing Filter ......................................................................13
4.7 Self Test ...........................................................................................13
4.8 Step/Direction Mode and CW/CCW Mode Jumper..........................13
5 Motor selection .......................................................................... 14
5.1 Recommended motors ....................................................................15
5.2 Torque-Speed Curves .....................................................................15
6 Error Codes ............................................................................... 16
7 Reference Materials .................................................................. 17
7.1 Mechanical Outline ..........................................................................17
7.2 Specications...................................................................................18
7.2.1 Electrical Specications...........................................................................18
7.2.2 Environmental Specications ..................................................................18
8 Contacting MOONS’.................................................................. 19

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SRAC2 User Manual
1 Introduction
Thank you for selecting the MOONS’ SRAC2 Step Motor Drive. The SRAC2 series AC input drives
are based on advanced digital current control technology and provide high torque, low noise and
low vibration. Many of the operational paramteres are switch selectable. We hope our dedication
to performance, quality and economy will make your motion control project successful.
1.1 Features
• Advanced digital current control provides excellent high speed torque
• Auto Setup measures motor parameters and congures motor current control and anti-
resonance gain settings
• Uses universal AC input 80 to 265 VAC, AC Input Voltage must be selected by switch
• Speed Range - up to 50 rps
• Microstep Resolution - switch selectable, 16 settings: 200, 400, 800, 1600, 3200, 6400,
12800, 25600, 1000, 2000, 4000, 5000, 8000, 10000, 20000, 25000 steps/rev
• Running Current - peak setting, switch selectable, 8 settings: 0.6A, 0.8A, 1.0A, 1.2A, 1.6A,
1.8A, 2.0A, 2.5A.
• Idle Current - automatic reduction of running current 1 second after the motor stops, switch
selectable, 2 settings: 50%, 90% of running current
• Anti Resonance - raises the system-damping ratio to eliminate midrange instability and allow
stable operation throughout the speed range of the motor, switch selectable, 2 settings for low
to high inertia loads
• Control Modes - Step/Direction pulse input or CW/CCW pulse input, internal jumper switch
selectable
• Input Signal Filter - lters out unwanted noise that can cause extra steps, switch selectable,
2MHz or 150KHz
• Step Smoothing Filter (Microstep Emulation) - performs high resolution stepping by
synthesizing coarse steps into ne micro-steps, switch selectable, ON or OFF
• Self Test - performs a1 rev, 0.5RPS, CW/CCW move test, switch selectable, ON or OFF
• Motor Selection - a 16 bit rotary switch is used to select the desired motor database which is
pre-loaded at the Factory

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SRAC2 User Manual
1.2 Block diagram
2 Mounting the Drive
The SRAC2 drive can be mounted only on the narrow side of the chassis. M4 screws should be
used in the two holes at the back of the drive.
The ampliers in the drive generate heat. To operate the drive continuously at maximum power
forced air cooling, as from a fan, should be provided.
Never use the drive in a space where there is no air ow or where other devices can cause the
surrounding air to be more than 40 °C. Never put the drive where it can get wet or where metal
particles can fall into it.
Never use the drive in a space where there is no air ow or where other devices can
cause the surrounding air to be more than 40 °C
Never put the drive where it can get wet or where metal particles can fall into it
STEP
DIR
OUT
EN
Gate
Drivers
(3)
Optical
Isolation
output
Optical
Isolation
output
Over
Current
Det.
DSP
5V
switching
reg
MOSFETs
(6) motor
Voltage
Det.
10V
reg
3.3V
reg
LED
SRAC2
Block Diagram
Step Noise Filter
Load Inertia
Smoothing Filter
Self Test
Step Res 1
Step Res 2
Step Res 3
Step Res 4
Current Set 1
Current Set 2
Current Set 3
Idle Current
80～135VAC
AC Input
135～265VAC

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SRAC2 User Manual
3 Connections
To use the SRAC2 Step Drive, the following items are needed:
• Universal AC input of 80 to 265 VAC
• Pulse & Direction signal
• A compatible step motor
• AC input voltage must be selected by switch

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SRAC2 User Manual
3.1 Connecting to Power
Use the supplied connector to connect to the AC supply according to the diagram below. Use 16
AWG wire for Line (L) and Neutral (N). Use 14 AWG for Earth Ground (G).
AC input voltage must be selected by switch.Check input voltage avoiding damage
before power on!
80Vac<Input AC Voltage<135Vac: set the switch on 115V Status
135Vac<Input AC Voltage<265Vac: set the switch on 230V Status
The SRAC2 contains an internal 5A fast acting fuse.
Care should always be taken when working with high voltages.
3.2 Connecting to a Motor
Motor connections should be made according to the following diagrams.
Earth Ground (green)
Neutral (white)
Line-hot (black)

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SRAC2 User Manual
White
Green
A
C
B
D
Brown
Yellow
Gray Blue
Red
Pink
A
Brown
Green
Pink
Blue
White
C
Yellow
D
Red
B
Gray

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3.3 Connecting the Inputs and Outputs
3.3.1 Step & Direction Inputs
The SRAC2 Step Drive has two high speed optically isolated inputs called STEP and DIR. They
accept 5 to 24 volt single-ended or di󰀨erential signals, up to 2MHz. The maximum voltage that can
be applied to the input is 28V.
The motor executes one step when the STEP input closes.
The direction of rotation is controlled by the DIR input state. A closed input (logic “0”) will result in
clockwise rotation, and an open input (logic “1”) will result in counterclockwise rotation.
SRAC2
SRAC2
SRAC2

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SRAC2 User Manual
3.3.2 EN input
The EN input enables or disables the drive amplier. It is an optically isolated input that accepts
a 5 to 24 volt single-ended or di󰀨erential signal. The maximum voltage that can be applied to the
input is 28V.
When EN input is closed, the driver amplier is deactivated, all the MOSFETs will shut down, and
the motor will be free. When EN input is open, the drive is activated.
When the drive has encountered an error and the fault is removed from the system, a falling signal
into the EN input will reset the error status and activate the drive amplier again.
SRAC2
SRAC2
SRAC2

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3.3.3 Fault Output
The FAULT Output is optically isolated. The maximum collector current is 100mA, and the
maximum collector to emitter voltage is 30 volts. The output can be wired to sink or source current.
When drive is working normally, the output is open. When the drive encounters an error, the output
closes.
SRAC2
SRAC2
SRAC2
SRAC2