GR214V MANUAL BULLETPROOF STEP MOTOR DRIVE
Thank you for purchasing Geckodrive’s GR214V motor control. The GR214V is a from-the-ground-up stepper motor controller design and uses multiple proprietary techniques to run a stepper motor smoother, quieter and with more power than other drives in its price range. This document seeks to quickly get your GR214V up and running and will explain each new feature and its utility for your application. Let’s begin: KEY NEW FEATURES OF THE GR214V: 1.
PHYSICAL DIMENSIONS AND PINOUT There are two connectors on the GR214V: A high power connector for motor and power supply connections called CN1 (P2 on the PCB) and a low power signal connector for I/O called CN2 (P1 on the PCB). The pinouts from left to right while facing the connector are below. All 8 pins on CN2 are optically isolated and there is no galvanic connection from any pin to the drive.
ELECTRICAL RATINGS SPECIFICATION Input voltage Output current DEVICE Input forward current continuous Input forward current peak Input forward voltage Input reverse breakdown voltage Output current HCPL2531 HCPL2531 HCPL2531 Input forward current continuous Input forward current peak Input forward voltage Input reverse breakdown voltage Collector current continuous Collector-emitter breakdown voltage MOCD DC output current NC7WZ HCPL2531 HCPL2531 MOCD MOCD MOCD MOCD MOCD PIN# 1 2 FUNCTION GND ST
CONNECTION DIAGRAM
STEP 1: APPLYING POWER AND CONNECTING A MOTOR POWER SUPPLY HOOKUP CN1 PIN 6 Power Ground Connect the power supply ground to this terminal CN1 PIN 5 Power (+) Connect the power supply “+” to this terminal The power supply voltage must be between 18 VDC and 80 VDC. The maximum power supply current required is 67% of the motor’s rated phase current. An unregulated power supply may be used as long as the voltage stays between the limits; keep the ripple voltage to 10% or less for best results.
STEP 2: SETTING MOTOR PHASE CURRENT Motor phase current may be set one of three ways: The onboard DIP switches, an external current set resistor or an external voltage input. All current settings will be in reference to the single phase peak current of the stepper motor. ONBOARD DIP SWITCH SETTING Please consult the diagram below for the proper switch setting for your motor phase current. Leave CN1 PIN2 floating if this option is being used. RED = OFF, GREEN = ON in the current set diagram.
EXTERNAL CURRENT SET RESISTOR An external current set resistor can be used, which will be connected between CN1 PIN 2 (Current Set) and CN1 PIN 3 (GND). The formula for the current set resistor is below: RI = IPEAK x 500 For a 3.2A motor the equation would look like below: RI = 3.2 x 500 RI = 1600 This would mean a 1.6K resistor would be the calculated resistance value. If the calculated resistance is a nonstandard value, it is safe to use the closest 5% resistor that is less than the calculated value.
STEP 4: SETTING STANDBY CURRENT After the GR214V has not received step pulses for one second it will enter standby mode, where it will limit current to a userset percentage of maximum current. The GR214V will enter reduced-heating switching mode during this time to further decrease motor temperature during times of inactivity. There are two ways to set the standby current value. ONBOARD STANDBY TRIMPOT Trimpot T2 on the GR214V is dedicated to setting the standby current value.
STEP 6: CONNECTING STEP AND DIRECTION SIGNALS CN2 PIN 1 Signal GND This pin is optional. This pin must connect to the controller ground terminal if the drive's FAULT and FULLSTEP outputs are going to be used; otherwise it can be left unconnected. CN2 PIN 2 Step This input pin connects to the controller's STEP output. The input accepts 3.3V and 5V logic level signals; if 3.3V logic is used, a 3.3VDC supply voltage from the controller must be connected to Pin 4. The maximum step pulse frequency is 2.
UNDERSTANDING OUTPUTS: FULLSTEP AND FAULT The two optically isolated and CMOS buffered outputs on the GR214V, FULLSTEP and FAULT, are covered below. Both are compatible with 5VDC and 3.3VDC logic. FULLSTEP: The GR214V has an output dedicated to pulsing on every full step location (full current to one winding and zero current in the other) on the motor, acting somewhat like a tachometer. This means every revolution would be 200 pulses on the FULLSTEP on a standard 1.8 degree stepper motor.
LED Fault Codes: Two LEDs give a status indication with either a solid color or a blink-blink-blink-off status code. A tertiary LED will only light in the event the fuse blows and is labeled on the PCB as “FUSE” above the LED as seen in Figure 1.
