Geckodrive GM215 User manual

1
GM215 MANUAL
STEP MOTOR DRIVE

2
Table of Contents
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Connector Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Quick Switch Setting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Motor Drive Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Motor Current Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Switch Settings and Connector Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Motion Controller Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Switch Settings and Connector Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Command Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Configure Axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Vector Axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Limit CW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Zero Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Acceleration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Respos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Move . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Home . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Jog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Speed Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Position Adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Goto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Call . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Wait . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
If-Then-Else . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Example Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Edit Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Download and setup GeckoMotion software . . . . . . . . . . . . . . . . . . . . 44
Create, Save and Open a Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Compile and Run a Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Step a Program for Testing/Troubleshooting . . . . . . . . . . . . . . . . . . . . . 50
Program Flash Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Display Device Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Input Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Assembler Listing and Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Using Other Serial Communication Programs . . . . . . . . . . . . . . . . . . . . . 53
Appendix A: Run Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Appendix B: Edit Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
E_Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Pause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Resume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

3
Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Program_Flash_Rom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Update_Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Query_Short . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Query_Long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Load_Program_Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Appendix C: Command Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Appendix D: More Sample Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Jog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Speed Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Position Adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Respos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Appendix E: Error Code and Fuse Replacement . . . . . . . . . . . . . . . . . . . . . . . . . 78
Appendix F: Update Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Appendix G: Inputs and Outputs Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Mechanical Switch Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Inductive Switch Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Optical Switch Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Hall Effect Switch Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Disclaimer, Manual Change Log - Manual last page . . . . . . . . . . . . . . . . . . . . . 87

4
The GM215 is a 7A, 80VDC step motor drive with an integrated motion controller. It can be used as a step and direction input
motor drive or as motion control enabled drive. The operating mode and mode related functions are set via the 10-position
slide switch on side of the drive. The GM215 has 3 opto-isolated inputs and 3 opto-isolated outputs. The function of the
input/outputs is also determined by the selected operating mode. The features of these operating modes are described below.
STEP MOTOR DRIVE FEATURES
The GM215 can operate as a conventional STEP and DIRECTION input step motor drive.
MICROSTEPPING: The GM215 has a 10 microstep native resolution; each full step angle of the motor is divided into 10 equally
spaced microsteps so a 200 step per revolution motor has 2000 stopping locations per revolution.
STEP PULSE MULTIPLIER: The GM215 synthesizes 10 microstep pulses for every full-step pulse and 5 microstep pulses for half-
step pulse. The GM215 acts like a full or half-step drive but motor has the smoothness of a 10-microstep drive.
SUB-MICROSTEPPING: For the 10 microstep resolution, each input step pulse is divided into 32 sub-microsteps resulting in a
motor smoothness equal to a 320 microstep drive.
MORPHING: The GM215 morphs from sine-cosine motor currents at low speeds to square-wave currents at high speeds. This
technique extracts the maximum possible power from the motor at higher speeds. Morphing begins at 240RPM and ends at
360RPM.
MID-BAND RESONANCE COMPENSATION: The GM215 uses active second-order damping to completely suppress a step motor’s
tendency to resonate and stall at medium speeds (300RPM – 900RPM). This results in stable motor operation in this region.
LOW SPEED RESONANCE COMPENSATION: Low speed resonances are motor vibrations at speeds below 120 RPM caused by
motor non-linearity. The PROFILE and ADJUST trimpots settings nulls these vibrations.
PROTECTION: The GM215 is protected against motor to ground and motor to motor output short-circuits. It is also protected
against reversed power supply polarity and power supply over-voltage. The internal fuse blows on polarity reversal and over-
voltage.
AUTOMATIC STANDBY CURRENT: If enabled, the motor phase current is reduced to 70% of the set value and the GM215 motor
switching topology is changed to a low heating recirculating mode. This happens 1 second after the last step pulse is received.
MOTION CONTROLLER FEATURES
The GM215 motion controller core is a 16-bit MCU, FPGA, Flash ROM and an RS485 interface transceiver. The motion controller
executes ASCII format commands sent from an external PC or from its own non-volatile memory.
'ON THE FLY' MOTION CONTROL: Acceleration, velocity and destination can be changed even while the motor is in motion. The
new values apply immediately.
MULTIPLE AXIS MOTION: Up to 4 GM215 drives can communicate with each other to execute coordinated multi-axis motion.
RUN FROM STORED PROGRAM: The GM215 can run stored motion programs from its non-volatile Flash memory without a
computer connected to it. The memory can store over 65,000 coordinates or program lines.
POWERFUL COMMAND-SET: The command-set includes 'if-then-else' conditional branching, looping and macros (subroutines).
It also includes canned high-speed HOME routines, JOG routines, SPEED control routines and more.
ANALOG INPUTS: The GM215 has on-board 3 trimpots to allow setting acceleration, velocity and destination instead of using
digital settings.
GENERAL PURPOSE I/O: The GM215 has three opto-isolated user defined inputs and three opto-isolated user defined outputs.
RS-485 INTERFACE: The GM215 has RS485 interfaces available. The default baud rate is 115,200.
BOOT-LOADER: The user can update the GM215 firmware using the built in boot-loader function.

5
CN1 CONNECTOR ASSIGNMENTS
Terminal Name Function
1GND DC Power supply (-)
2VDC+ DC Power supply (+)
3 A Motor winding A
4/A Motor winding A
5 B Motor winding B
6/B Motor winding B
GND (TERMINAL 1)
Connect the power supply '-' to this terminal. This connection must be hard-wired to the power supply.
VDC+ (TERMINAL 2)
Connect the power supply '+' to this terminal. The power supply voltage must be between 18 VDC and 80 VDC and this
connection must be hard-wired to the power supply. Do not use a switch, relay contact or any other device in series with this
wired connection.
A (TERMINAL 3)
/A (TERMINAL 4)
Connect one motor phase winding to these terminals.
B (TERMINAL 5)
/B (TERMINAL 6)
Connect the other motor phase winding to these terminals.
TRIMPOT ADJUSTMENTS
TRIM1 and TRIM2 are used to maximize motor smoothness at speeds below 50 RPM. The Digital Self-Test feature can useful in
making these adjustments. While the motor is turning, adjust TRIM1 for minimum motor vibration.
The rest of this user's manual is divided into two sections. Use the GM215 STEP MOTOR DRIVE MANUAL if the GM215 is used
as a conventional step motor drive. Use the GM215 MOTION CONTROLLER MANUAL if the GM215 motion controller is used.

6
QUICK SWITCH SETTING GUIDE
For SW5 to SW10, see NOTE.
For more details, see Motor Drive Mode and Motion Controller Mode Switch Settings.
For current setting, see Fig 2 on page 7; for axis setting, see Fig 4 on page 11.
Figure 1: QUICK SWITCH SETTING
STEP/DIR full-step (Motor DriveMode)
1 2 3 4 5 6 7 8 9 10
ON
Digital SELF-TEST
1 2 3 4 5 6 7 8 9 10
ON
Analog SELF-TEST
1 2 3 4 5 6 7 8 9 10
ON
STEP/DIR half-step (Motor DriveMode)
1 2 3 4 5 6 7 8 9 10
ON
STEP/DIR 10-microstep (Motor DriveMode)
1 2 3 4 5 6 7 8 9 10
ON
RUN Program-X axis (MotionController Mode)
1 2 3 4 5 6 7 8 9 10 Set SW3-SW4 for axis type
EDIT Program-X axis (MotionController Mode)
1 2 3 4 5 6 7 8 9 10 Set SW3-SW4 for axis type
NOTE:
SW5 = ON for NEMA-23or smaller
SW5 = OFF for NEMA-34or larger
2) SW6-SW10 are for current setting
1) SW5 is for motor size setting:
= SW is "ON"
= SW is "OFF"

7
GM215 STEP MOTOR DRIVE MANUAL
This manual covers the GM215 when it's used as a conventional STP/DIR input step motor drive. Go to the GM215 MOTION
CONTROLLER MANUAL if the GM215 is used as a motion controller and motor drive.
MOTOR CURRENT SETTING
Figure 2: MOTOR CURRENT SETTING

8
SWITCH SETTINGS AND CONNECTOR WIRING
CAUTION:
Perform the following steps with the power supply turned 'OFF' until a step says it is OK to turn the power supply 'ON'. Do not
change the current set switches after setup while the motor is powered.
The following switch settings and their function only applies to the Motor Drive Mode. The same switches have completely
different functions in the Motion Controller Mode.
STEP 1: SELECT MOTOR DRIVE MODE
SW1 'ON' Select step motor drive mode operation. In this mode the GM215 acts like a STEP / DIRECTION motor drive and the
internal motion controller isn't used.
STEP 2: SELECT MOTOR CURRENT
Use the following chart to set the GM215 to the motor's phase current rating. If a motor has a rated current that isn't listed in
the table below, set the current to the first setting that is greater than the motor's rated current.
Figure 3: MOTOR DRIVE MODE SETUP
STEP 3: SELECT MOTOR SIZE
Switch 5 must be set to the motor frame size.
SW5 ‘ON’ The motor is a NEMA-23 size or smaller.
SW5 'OFF' The motor is a NEMA-34 size or larger.

9
STEP 4: SELECT SELF-TEST
This step is optional and it can be skipped. Self-Test can also be used after setup is completed or at any other time when it is
necessary to verify the GM215 is working correctly. It can be useful when debugging a controller to GM215 interface. When
finished with Self-Test, restore switches SW2, SW3, and SW4 to their previous settings to exit the Self-Test routine.
Two Self-Test routines available, Digital and Analog:
DIGITAL SELF-TEST
SW2 'ON'
SW3 'OFF'
SW4 'OFF'
In this setting, a 1.8 degree motor continuously turns 5 revolution clockwise and counter-clockwise at low, medium, and high
speed.
ANALOG SELF-TEST
SW2 'OFF'
SW3 'OFF'
SW4 'OFF'
In this setting, the motor's rate of acceleration is set by TRIM3, its velocity is set by TRIM5. The motor will move 5 revolutions in
either direction before reversing.
STEP 5: SELECT STEP SIZE
The GM215 can move in full-step, half-step or 10-microstep increments.
FULL-STEP
SW3 'ON'
SW4 'ON'
Every step pulse will move a 1.8 degree motor 1.8 degrees. The motor will move with 10-microstep smoothness which greatly
limits low speed vibration.
HALF-STEP
SW3 'ON'
SW4 'OFF'
Every step pulse will move a 1.8 degree motor 0.9 degrees. The motor will move with 10-microstep smoothness to limit low
speed vibration.
10-MICROSTEP
SW3 'OFF'
SW4 'ON'
Every step pulse will move a 1.8 degree motor 0.18 degrees. The motor will move with 320-microstep smoothness which makes
the motor's motion continuous instead of step-wise even at very low speeds (less than 1 full-step per second).
STEP 6: SELECT STANDBY CURRENT REDUCTION
Standby Current Reduction is a method of reducing motor heating while a motor is idle and not moving. This is accomplished
reducing motor current to 70% of the set value if this setting is enabled. The only adverse effect is the motor's holding torque is
reduced to about 75% of its nominal value. If the motor has a back-driving load such as holding up a weight against gravity, this
selection may not be advisable.
When enabled, the current reduction goes into effect 1 second after the last step pulse is received. The motor stays in this state
until a new step pulse sent, at which time full current is restored very quickly.
SW2 'ON' enables current standby. The current is reduced while a motor is idle.
SW2 'OFF' disables current standby. An idle motor will stay at full current.
THIS COMPLETES THE SWITCH SETUP

10
CN2 CONNECTOR ASSIGNMENTS
Connector CN2 terminals 6 through 12 are unused in the Step Motor Drive mode. Terminals 1, 2 and 3 are common cathode
opto-isolated inputs with 200 Ohm current limit resistors. The inputs work with 2.5V, 3.3V and 5V logic levels. Logic 1 input
current is 2 mA. The output is an open collector opto-isolator that has a 10 mA current sink rating (see Appendix G for more
details).
Terminal Function I/O
1 DISABLE INPUT
2 DIRECTION INPUT
3STEP INPUT
4 COMMON EXTERNAL GROUND
5 FAULT OUTPUT
DISABLE (TERMINAL 1)
The motor drive is ENABLED when this input is unused or has a logic 0 applied. The motor drive is DISABLED when this input has
a logic 1 applied. When DISABLED, the motor current goes to zero, there is no switching activity on the motor outputs and the
motor free-wheels (detent torque). The motor position is restored if no step pulses have been sent while disabled.
DIRECTION (TERMINAL 2)
The state of this input determines the direction a motor will move when a step pulse is received. The DIRECTION logic level must
be stable 250ns before the active edge of the step pulse.
STEP (TERMINAL 3)
A positive edge on this input (logic 0 to logic 1) causes the motor to move one increment of motion. The minimum logic 1 time
is 1 microsecond and the minimum logic 0 time is 3 microseconds.
COMMON (TERMINAL 4)
This is the ground terminal for the DISABLE, DIRECTION and STEP inputs and the FAULT output. It must go to the ground
terminal of the controller that generates these inputs.
FAULT (TERMINAL 5)
This output goes to a logic 1 when the drive goes into protective shutdown because of over-voltage, over-current or over-
temperature. Once the cause for the FAULT is corrected, the FAULT output can be cleared by cycling the power supply or the
DISABLE input.
When finish switch setup and wiring, it is OK to turn on power supply.
END OF GM215 STEP MOTOR DRIVE MANUAL

11
GM215 MOTION CONTROLLER MANUAL
This manual covers the GM215 when it's used as a motion controller and motor drive. Go to the GM215 STEP MOTOR DRIVE
MANUAL if the GM215 is used as a conventional STP/DIR input step motor drive.
SWITCH SETTINGS AND CONNECTOR WIRING
Figure 4: MOTION CONTROLLER MODE SETUP

12
GM215 SETUP FOR MOTION CONTROLLER MODE
CAUTION: The following switch settings and their function only applies to the Motion Controller Mode. The same switches have
completely different functions in the Step Motor Drive mode. Turn the power supply 'OFF' and take care to set the switches to
their correct settings when changing the operating mode.
STEP 1: SELECT MOTOR DRIVE MODE SW1 'OFF' Select motion controller mode operation.
STEP 2: SELECT MOTOR SIZE SW5 ‘ON’ The motor is a NEMA-23 size or smaller.
SW5 'OFF' The motor is a NEMA-34 size or larger.
STEP 3: SELECT AXIS NAME
The axis name tells a GM215 which commands and communications apply to it and which it can ignore.
X AXIS: SW3 'ON' Y AXIS: SW3 'ON' Z AXIS: SW3 'OFF' W AXIS: SW3 'OFF'
+SW4 'ON' +SW4 'OFF' +SW4 'ON' +SW4 'OFF'
STEP 4: SELECT OPERATION The Motion Controller has 2 operating modes: EDIT and RUN.
EDIT MODE SW2 'OFF'
The EDIT mode is used to edit an existing user program or to write a new user program. This mode requires a serial connection
(RS-485) between PC and GM215. The code can be flash to GM215 on board ROM and be stored permanently.
Edit mode is used as a debug tool. Each line of code can be single stepped. For high performance motion, please use RUN
mode.
RUN MODE SW2 'ON'
In RUN mode, one or more GM215 can execute a user program stored in Flash ROM without requiring a computer connection.
NOTE: A RESET/START SWITCH OR BUTTON IS REQUIRED TO USE RUN MODE. See figure 7 – page 16 for more detail.

13
CN2 CONNECTOR ASSIGNMENTS
Terminals 1, 2 and 3 are opto-isolator LED anode inputs in series with 200 Ohm current limit resistors (see Appendix G for more
details). The LED cathodes go to the COMMON terminal. The inputs work with 2.5V, 3.3V and 5V logic levels. Minimum logic 1
input current is 2 mA. Terminals 5, 6 and 7 are three opto-isolated collector outputs that have a 10 mA current sink rating and
their emitters go to the COMMON terminal (see Appendix G for more details).
Terminal Name Function
1 IN1INPUT
2 IN2INPUT
3 IN3INPUT
4 COMMON
5 OUT1 OUTPUT
6 OUT2 OUTPUT
7 OUT3 OUTPUT
8 ANALOG GND ANALOG GND
9 ANALOG IN ANALOG INPUT
10 RS485 A SERIAL PORT
11 RS485 B SERIAL PORT
12 RS485 COM SERIAL PORT GROUND
IN 1 (TERMINAL 1)
This is a low-speed opto-isolated general purpose input. A logic '1' signal turns the input 'ON'. The signal ground is the
COMMON terminal (term 4). At RUN mode its dedicated function is RESET. (See figure 7)
IN 2 (TERMINAL 2)
This is a high-speed opto-isolated general purpose input. A logic '1' signal turns the input 'ON'. The signal ground is the
COMMON terminal (term 4). Its dedicated function is the home switch input if the HOME command is used. (See
figure 6)
IN 3 (TERMINAL 3)
This is a high-speed opto-isolated general purpose input. A logic '1' signal turns the input 'ON'. The signal ground is the
COMMON terminal (term 4). It has no dedicated function.
COMMON (TERMINAL 4)
This terminal is the signal ground for IN 1, IN 2, IN 3, OUT 1, OUT 2 and OUT 3 opto-isolators.
OUTPUT 1 (TERMINAL 5) GENERAL PURPOSE OUTPUT
OUTPUT 2 (TERMINAL 6) GENERAL PURPOSE OUTPUT
OUTPUT 3 (TERMINAL 7) GENERAL PURPOSE OUTPUT
ANALOG INPUT (TERMINAL 8 & 9) Used with command IF_THEN_ELSE and COMPARE.
For example IF x VIN IS > GOTO label1.
Notes: This analog input is designed for a voltage feedback from external system, and it is a source of flow control command.
It is NOT designed for using this analog value to control motor speed.
Analog speed control can be done by using on board trimpots or replacing trimpots with analog voltage source (0-3.3v).
RS485 (TERMINALS 10, 11, 12)
These terminals are used by the RS-485 transceiver. The RS-485 COM terminal connects to the GM215 circuit ground through a
33 Ohm resistor used to limit ground loop currents. All GM215s using the RS-485 serial interface must share a common power
supply ground. The A input has a 3K pull-up resistor to 3.3V while the B input has a pull-down 3K resistor to ground. These
terminals are NOT opto-isolated.

14
MULTI-AXIS POINT-TO-POINT MOTION
Point-to-point multi-axis motion is used when it does not matter what path is taken to a coordinate location. This is perfectly
acceptable in many application because point-to-point motion takes the shortest possible time moving to a new location.
Each axis can use its own programmed accelerate, velocity and destination values for motion. The path taken to the destination
probably won't be in a straight line because each axis' acceleration, velocity and destination can be different so each axis will
take a different amount of time moving to the new location. All of the axis must finish moving before they can move to the next
programmed location.
MULTI-AXIS VECTOR MOTION
Unlike point-to-point motion, a vector motion path is along a straight line from the last coordinate location (previous x, y, and z)
connecting to the next coordinate (next x, y, and z). The rate of acceleration and velocity is independent of the vector direction.
Oftentimes the coordinates are short line segments that, when concatenated, linearly approximate arbitrary 2D or 3D curves.
Vector motion requires all GM215s begin and finish executing each vector segment at precisely the same time and this requires
that all GM215's microprocessor clocks be phase locked to the master x-axis clock. Besides communication tasks, the master x-
axis GM215 uses the RS-485 serial bus to transmit a synchronizing signal to all slave axis GM215s.
For reason of simplicity, each axis is programmed with exactly the same user program. Each GM215 calculates the vector length
from the coordinates stored in the program but only extracts the vector component that matches that motion controller's
designated name. The vector component is then processed by a motion control algorithm and the results are sent to the motor
drive section of the GM215. Each GM215 then drives its attached axis motor and all the axis motor's movements combine to
reconstitute the vector as a 2D or 3D motion in the motor-driven mechanism.
I/O SCHEMATIC
The opto-isolator LED series current limit resistors are 200 Ohms on the IN1, IN2, and IN3 inputs. The input current is 17mA at
+5A, 9mA at +3.3V and 2mA at +2.5V. The minimum operating input current for all inputs is 1.6mA (see Appendix G for more
details). IN1 is a low-speed opto-isolator having a 50uS propagation delay. IN2 and IN3 are high-speed opto-isolators and have a
1uS propagation delay. OUT1, OUT2, and OUT3 are low-speed opto-isolators having a 50uS propagation delay (see Appendix G
for more details).
Figure 5: I/O SCHEMATIC

15
HOME/LIMIT SWITCH WIRING
When using command HOME, a hardware connection is a must. Default home switch input is IN2.
When using command SPEED CONTROL, it is possible to use two limit switches. Default limit switches input are IN2 and IN3.
Figure 6: How to wire the HOME switches

16
RUN MODE START/RESET WIRING
After flash the on board ROM, GM215 can run at RUN MODE.
RUN mode requires a START/RESET button or switch to control the progress. Without it, master and slave drives in a multiple
drives system cannot be synchronized well. Default start/reset input is IN1. Once applied a 5v, all drives will be reset and hold
the reset status until 5v is released.
Figure 7: How to wire the RESET switch for RUN mode

17
COMMAND SET
The GM215 works as a multiple-axis motion controller when 2 or more drives are connected via its RS-485 interface. When used
this way, one GM215 must be named as the X drive (SW3 = ON, SW4 = ON) to make it the master drive. Each of other drives
must be set to a unique axis name (Y, Z, or W) using SW3 and SW4.
Once connected and named, the other slaved drives automatically synchronize themselves to the X-drive's microprocessor clock
via sync pulse sent over the RS-485 interface. The drives communicate with each other and behave as if they were a single, 4-
axis motion controller. All the drive's Flash ROMs are programmed with same user's application program; each drive executes
only those commands that match the drive's name. This simplifies programming, editing and program maintenance because the
drives are interchangeable. A single .bin file sent from the GeckoMotion application is written to all drives' Flash ROMs
simultaneously.
Once a user's program is debugged and flashed to the drives, the drives can be put into RUN mode (SW1 = OFF, SW2 = ON) and
the PC interface can be disconnected. The drives will execute the user's program from its non-volatile memory without a PC
connection.
The drive's Flash ROM stores up to 65,536 lines of commands and all commands have fixed 2-word (32-bit) length. Appendix A
shows how these commands are coded to this 2-word binary format used by the GM215. This is to allow a user to write their
own GUI if they wish to do so. The RS-485 uses a standard UART set to 115,200 baud, 8-bit data, no parity and 1 stop bit.
Commands can be entered and debugged while the GM215 is in the EDIT PROGRAM mode (SW1, SW2 OFF). The GM215 must
be connected to PC via its RS-485 interface while in the EDIT PROGRAM mode and the PC must be running the GeckoMotion
application.
The commands have 3 main groups; Configuration commands, Motion commands and Program Flow commands:
CONFIGURATION COMMANDS:
CONFIGURE AXIS Set the axis motor current and other parameters
ACCELERATION Set axis rate of acceleration
VELOCITY Set axis target velocity
ANALOG INPUTS Switch the axis between digital and analog inputs
VECTOR AXIS Combine 2 or more axis for vector motion
LIMIT CW Set the axis CW travel limit
ZERO OFFSET Move axis CW from home a distance equal to offset value
MOVING AVERAGE Filter the axis motion using a moving average filter (future)
RESPOS Reset motor position
MOTION COMMANDS:
MOVE Move axis to an absolute or relative destination
HOME Home the axis to a hardware switch location
JOG Move the axis using external inputs
SPEED CONTROL Operate the axis in velocity mode
POSITION ADJUST Adjust the axis position using external inputs
PROGRAM FLOW COMMANDS:
GOTO Go to a program-line, also Loop (4 nested loops allowed)
CALL Call a subroutine and return (4 nested calls allowed)
IF THEN ELSE If a condition is met then go to program-line 'n', else go to next program-line
WAIT Wait a period of time, then go to next program-line
RETURN This command is used to end a CALL function
MISCELLANEOUS COMMANDS:
OUTPUT Turn a hardware output ON or OFF
COMPARE Stores a variable used by the IF-THEN-ELSE command
CHANGE SCALE Change the motion coordinate scale (future)
ROTATE Rotate the axis coordinates by an angular value (future)
TANGENT Rotate an axis to point in the motion direction (future)
MIRROR Mirror the axis coordinates vertically or horizontally (future)
ENCODER Axis tracks a quadrature encoder (future)

18
The GeckoMotion host program uses labels for program flow commands. This greatly eases the burden of writing and
debugging the user program:
00067 PREVIOUS COMMAND
00068 IF Z INPUT 2 IS OFF GOTO label_1 An IF command tests if the Z axis input 2 is off. If true, the program jumps to
'label_1:'
00069 NEXT COMMAND If false, the program goes to the next command
---- ------
---- ------
---- ------
00234 label_1:
00235 SOME OTHER COMMAND Program jumped here because the Z axis input 2 is off.
---- ------
Note: please see Example code on pages 34-40 and Sample code (Appendix D) on pages 74-77.

19
________________________________________________________________________________________________________
CONFIGURE AXIS CONFIGURATION COMMAND
Syntax: a CONFIGURE: i AMPS, IDLE AT p % AFTER s SECONDS<ENTER>
Operands: a = X, Y, Z, W
CONFIGURE = configure axis command
0.0 <= i <= 7.0
00 <= p < 100
00.0 <= s =< 25.5
Operation: Sets the motor's operating parameters.
Type: The command settings are global.
Description: This command sets:
1. The selected axis motor phase current from 0 Amps to 7 Amps per phase in 100mA increments. Refer to the motor data-sheet
for the correct current setting for motor being used.
2. Sets the motor's standby idle current while the motor is stopped to reduce motor heating. The motor standby current is the
set percentage times the motor's set phase current. The drive also goes into recirculating mode switching while in idle to reduce
motor eddy-current heating.
3. Sets the time delay before going into the idle mode after the motor stops. Motor current is restored to its full set value
immediately after the motor must run again.
Example:
X CONFIGURE: 1.8 AMPS, IDLE AT 71% AFTER 2.5 SECONDS <ENTER>
X means the CONFIG command settings apply to the X axis motor.
CONFIGURE selects the CONFIG command.
1.8 AMPS is the motor phase current setting.
71 means reduce the motor phase current to 71% of the set AMPS value while the motor is stopped.
2.5 SECONDS is the delay time before current is reduced after the motor stops.
<ENTER> indicates the command is finished.
Note: please see Example code on pages 34-40 and Sample code (Appendix D) on pages 74-77.
________________________________________________________________________________________________________
ANALOG INPUTS CONFIGURATION COMMAND
Syntax: ANALOG INPUTS TO a, a, a, a <ENTER>
Operands: a = axis X or Y or Z or W
Operation: Sets inputs to analog for selected axis.
Type: The command settings are global.
Description:
This command sets analog voltage inputs values for acceleration, velocity and position settings for the selected axis.
Example:
ANALOG INPUTS TO Z, X <ENTER>
ANALOG INPUTS is the ANALOG INPUT command
Z includes the Z axis for analog inputs for Acceleration, Velocity and Position values.
, means another axis is to be included.
X includes the X axis for analog inputs for Acceleration, Velocity and Position values.
<ENTER> completes the command. The Y and W axis weren't included so will use digital values for
Acceleration,
Velocity and Position in commands that require these settings.
Note: please see Example code on pages 34-40 and Sample code (Appendix D) on pages 74-77.

20
________________________________________________________________________________________________________
VECTOR AXIS CONFIGURATION COMMAND
Syntax: VECTOR AXIS ARE a, a, a, a <ENTER>
Operands: a = axis X or Y or Z or W
Operation: Associates which axis are to be combined for vector motion.
Type: The command settings are global.
Description:
This command selects which axis will be combined for vector motion. Vector velocity is the same regardless of the vector's
direction, all associated axis motion begins and ends at the same time and the path taken will be a straight line connecting the
origin and destination coordinates.
Example:
VECTOR AXIS ARE X, Y, W <ENTER>
VECTOR AXIS ARE is the VECTOR AXIS command
X means include the X axis.
, is the delimiter indicating another axis is to be included.
Y means also include the Y axis.
, means another axis is to be included.
W means also include the W axis.
<ENTER> indicates the command is finished.
Note: please see Example code on pages 34-40.
________________________________________________________________________________________________________
LIMIT CW CONFIGURATION COMMAND
Syntax: a LIMIT CW n <ENTER>
Operands: a = axis X or Y or Z or W
0 =< n <= 16,777,215
Operation: Sets the axis clockwise travel limit from the home position.
Type: The command settings are global.
Description:
This command sets the maximum distance for any motion away from the HOME position. Its function is to prevent damage to a
mechanism if the axis is inadvertently commanded to move beyond the mechanism's safe limits. This can occur if a
programming error is made or an axis is jogged past this limit if the limit is exceeded. The motor is decelerated to a stop and
locked. Use software reset (press E-STOP button in GUI) or hardware reset (IN1 in RUN mode) to unlock the motor.
This command is optional. If the command isn't used, the default value is 16,777,215.
Example:
Z LIMIT CW 987654 <ENTER>
Z means the Z axis is selected
LIMIT CW means the LIMIT CW command
987654 sets the axis travel limit 987,654 increments of motion away from the home location.
<ENTER> indicates the command is complete.
Note: please see Example code on pages 34-40.