MMP SA-2550A Manual

Servo amplifier

Hide thumbs

Table Of Contents

Table of Contents

Quick Links

Download this manual

Description

The MMP SA-2550A PWM servo amplifier is designed to

drive brushed or brushless type DC motors at a high

switching frequency. A single red/green LED indicates

operating status. The drive is fully protected against

over-voltage, under- voltage, over-current, over-heating

and short-circuits across motor, ground and power

leads. Furthermore, the drive can interface with digital

controllers or be used stand-alone, and requires only a

single unregulated DC power supply. Loop gain, current

limit, input gain and offset can be adjusted using 14-

turn potentiometers. The offset adjusting potentiometer

can also be used as an on-board input signal for testing

purposes. This drive can use quadrature encoder inputs,

Hall Sensors, or a tachometer for velocity control.

Four Quadrant Regenerative Operation

DIP Switch Selectable Modes

DIP Switch Configurable Loop Tuning

DIP Switch Configurable Current Scaling

DIP Switch Configurable Tachometer

Scaling

Selectable Inhibit Logic

High Switching Frequency

Digital Fault Output Monitor

MODES OF OPERATION

Current

Encoder Velocity

Hall Velocity

Tachometer Velocity

Duty Cycle (Open Loop)

COMMAND SOURCE

±10 V Analog

FEEDBACK SUPPORTED

Hall Sensors

Incremental Encoder

Tachometer (±60 VDC)

MMP SA-2550A

SERVO AMPLIFIER

Peak Current

Continuous Current

Supply Voltage

Features

Power Range

On-Board Test Potentiometer

Offset Adjustment Potentiometer

Adjustable Input Gain

Selectable 120/60 Hall Commutation Phasing

Encoder Velocity Mode

Hall Velocity Mode

Velocity Monitor Output

Current Monitor Output

Drive Status LED

MOTORS SUPPORTED

Three Phase (Brushless)

Single Phase (Brushed, Voice Coil, Inductive Load)

COMPLIANCES & AGENCY APPROVALS

cUL

CE Class A (LVD)

CE Class A (EMC)

RoHS II

50 A

25 A

20 - 80 VDC

Table of Contents

Need help?

Do you have a question about the SA-2550A and is the answer not in the manual?

Questions and answers

Summary of Contents for MMP SA-2550A

Page 1 SERVO AMPLIFIER Description Power Range Peak Current 50 A The MMP SA-2550A PWM servo amplifier is designed to drive brushed or brushless type DC motors at a high Continuous Current 25 A switching frequency. A single red/green LED indicates operating status. The drive is fully protected against...
Page 2: Table Of Contents
MMP SA-2550A Table of Contents Block Diagram ................
Page 3: Block Diagram
Note that the above diagram is for a brushless motor with Hall effects and with or without an encoder. If you have purchased other hardware to run with the amplifier then the above wiring scheme does not apply. Contact MMP for more details.
Page 4: Specifications
MMP SA-2550A SPECIFICATIONS Power Specifications Description Units Value DC Supply Voltage Range 20 - 80 DC Bus Over Voltage Limit DC Bus Under Voltage Limit Maximum Peak Output Current Maximum Continuous Output Current Maximum Continuous Output Power at Continuous Current...
Page 5: Pin Functions
MMP SA-2550A PIN FUNCTIONS P1 - Signal Connector Name Description / Notes +10V 3mA OUT ±10 V @ 3 mA low power supply for customer use. Short circuit protected. Reference ground SIGNAL GND common with signal ground. -10V 3mA OUT +REF IN Differential Reference Input (±10 V Operating Range, ±15 V Maximum Input)
Page 6: Hardware Settings
MMP SA-2550A HARDWARE SETTINGS Configuration Switch Functions Setting Description Duty Cycle mode selector. Activates internal PWM feedback. Duty Cycle mode Other modes Inhibit logic. Sets the logic level of inhibit pins. Drive Inhibit is active low Drive Inhibit is active high Test/Offset.
Page 7 MMP SA-2550A (Note : Drive cover must be removed to access SW4) Description Setting Advanced Tuning See SW4 table in Loop Tuning Switch Functions section for (Velocity Loop Integrator Capacitance) switch settings and corresponding capacitance values. Continuous Current Scaling. Configures the drive to set the...
Page 8: Importance Of Proper Current Monitoring
�� Due to the nature of the MMP SA-2550A the input and output currents usually correlate but are not always equal. To ensure the motor is receiving the proper amount of current we highly recommend utilizing the current monitor pin (P1-8, see page 5, Pin Functions table for further details) and measuring the voltage relative to signal ground as shown below.
Page 9: Using An Encoder Feedback With A Servo Amplifier
Using an Encoder Feedback with a Servo Amplifier Encoders can be used with the MMP SA-2550A to provide feedback to the amplifier and control speed of the motor. The default setting on the servo amplifier is duty cycle mode. This mode does not use motor feedback. If motor speed as feedback is required then using an encoder as feedback to the Servo Amplifier is recommended.
Page 10 MMP SA-2550A If an external command signal (usually 10 VDC) is used in place of a potentiometer then wire as shown below. Remove connection to P1-1 and connect the signal positive to pin 5 (for %0-%100 POT effect). Ensure VCOM is grounded to P1-2.
Page 11: Running A Brushed Dc Motor With The Servo Amplifier
Follow the below steps to configure a SA-2550A to run a brushed, DC motor. Switch Setting Set the 120°/60° PHASING dipswitch to OFF for 60° phasing. For the SA-2550A this is SW 1-10. The OFF position is toward the outside of the servo amplifier as shown in the picture below.
Page 12: Reversing A Brushless Motor
MMP SA-2550A How to reverse a brushless DC motor Figure 2. Typical Wiring Solution of a Brushless Motor with Encoder. The typical wiring solution shown above results in the brushless motor to run forward (CW rotation) with the potentiometer max at the CW position.
Page 13: Regenerative Braking With The Servo Amplifier
MMP SA-2550A Regenerative braking with the SA-2550A Regeneration and Shunt Regulators Use of a shunt regulator is necessary in systems where motor deceleration or a downward motion of the motor load will cause the system’s mechanical energy to be regenerated via the drive back onto the power supply.
Page 14 MMP SA-2550A These energy terms can be broken down into the approximate mechanical and electrical terms - capacitive, kinetic, and potential energy. The energy equations for these individual components are as follows: �� = ��ℎ ��...
Page 15 MMP SA-2550A Figure 4. Example of motor profile during operation. When choosing a shunt regulator, select one with a shunt voltage that is greater than the DC bus voltage of the application but less than the over voltage shutdown of the drive. Verify the for a shunt regulator by operating the servo drive under the worst-case braking and deceleration conditions.
Page 16: Loop Tuning Switch Functions
MMP SA-2550A Loop Tuning Switch Functions In general, the drive will not need to be further tuned beyond the default configuration. However, for applications requiring more precise tuning, DIP switches can be used to adjust the current and velocity loop tuning values. Some general rules of thumb to follow when tuning the drive are: ...
Page 17: Mechanical Information
MMP SA-2550A MECHANICAL INFORMATION P1 - Signal Connector Connector Information 16-pin, 2.54 mm spaced, friction lock header Details Molex: P/N 22-01-3167 (connector) and P/N 08-50-0114 (insert terminals) Mating Connector Included with Drive 15 VEL MONITOR OUT 13 HALL 2 11 GND...
Page 18: Mounting Dimensions
MMP SA-2550A MOUNTING DIMENSIONS Midwest Motion Products DESIGN, MANUFACTURING & DISTRIBUTION - MOTION CONTROL EQUIPMENT Page 18 of www.midwestmotion.com email: sales@midwestmotion.com...
Page 19: Troubleshooting Guide Red Led Causes And Solutions
What a red LED indicator means and how to fix it. How to perform current loop tuning on the SA-2550A. Adjusting the Command Signal Curve using the built in potentiometers of the SA-2550A servo amplifier. Red LED indicator meaning and methods of correction A red LED can indicate any of the following fault conditions: ...
Page 20 MMP SA-2550A A shunt regulator may be necessary to dissipate the energy regenerated by the system. See the section on regenerative braking, pages 13-15 for more details. Invalid Hall State Brushless drives have 3 Hall sensor inputs that determine a Hall state. The drive will fault if an invalid Hall state is detected.
Page 21 MMP SA-2550A Short Circuit The drive will fault if a short circuit is detected on the output. This can occur if any of the motor phases are shorted to power ground, AC ground, or shorted together. Use a DMM to measure the resistance between two points of interest. A 0 ohm resistance indicates a short circuit.
Page 22: Current Loop Tuning
To perform current loop tuning, first locate the relevant potentiometer (POT 1) as shown below: Figure 5. Location of current loop tuning potentiometer on SA-2550A Servo Amplifier. Note: If you are running in current mode then current loop tuning is not necessary; the instructions below only apply while in velocity mode.
Page 23: Command Curve Adjustment
MMP SA-2550A Adjusting the Command Signal Curve using the built in potentiometers of the SA-2550A servo amplifier. Depending on how the built in potentiometers are preset the correlation of command voltage to motor speed may result in less control of motor speed then desired. A typical command curve would appear as below if potentiometer at full CCW is 0% and full CW is 100% output.
Page 24 MMP SA-2550A The respective potentiometers have the following effects on the command curve: As noted in the Potentiometer Functions table on page 6, each potentiometer has approximately 12 active turns. Turning the potentiometer beyond these active points will have no effect on the command curve.