MOTKA MK-200C User manual

M
MK K- -2 20 00 0C C
U
Us se er r’ ’s s M Ma an nu ua al l
Revision 1.1
MOTKA LLP

Table of Contents
1
1. .Introduction............................................................................................................5
2
2. .Getting Started.......................................................................................................8
2.1. Connecting the Power Supply..........................................................................10
2.2. Connecting the Host.........................................................................................10
2.3. Selecting Servo or Stepper...............................................................................11
2.4. Connecting Servo Motor..................................................................................11
2.5. Connecting Stepper Motor...............................................................................13
2.6. Connecting the Limits......................................................................................14
2.7. Connecting the Home Indicator.......................................................................15
2.8. Testing Our Connections .................................................................................16
2.9. Design Examples .............................................................................................17
3
3. .Package Information............................................................................................22
4
4. .Software Tools.....................................................................................................23
5
5. .Command Basics .................................................................................................24
6
6. .Revision History ..................................................................................................25

3
List of Figures
Figure 1 – Elements of motion control.....................................................................5
Figure 2 – The MK-200C 2-Axis Motion Controller................................................6
Figure 3 - MK-200C ....................................................................................................8
Figure 4 – Power supply scheme...........................................................................10
Figure 5 – RS-232C-to-RS232C interface with host ...........................................11
Figure 6 – Connecting to a brushless servo motor to MK-200C .......................12
Figure 7 – Connecting to a brushed servo motor to MK-200C..........................13
Figure 8 – Connecting to a stepper motor to MK-200C......................................13
Figure 9 – Connecting to forward and reverse limits to MK-200C....................15
Figure 10 – Connecting to home indicator............................................................16
Figure 11 – Home operation....................................................................................16
Figure 12: MK-200C package outline....................................................................22

4
List of Tables
Table 1 – MK-200C terminal definitions..................................................................9
Table 2 - Document revision history.......................................................................25

5
1
1. . Introduction
This User Manual targets application developers. It provides complete
information on how to use the MK-200C.
For information on programming and the complete list of command
references, please refer to the Command Reference manual.
MK-200C is a 2-Axis Motion Controller that facilitates implementation of
motion control applications with simplicity, shortens time-to-market, and
achieves optimal cost-effectiveness. It is suitable for scientific, industrial
automation, robotic applications and hobby.
MK-200C is a fully functional motion controller requiring only an external
amplifier to complete a position control application. It is driven by a host
through an asynchronous serial port (RS-232C). Figure 1 shows the
elements of motion control application using MK-200C. Its servo
compensation uses 32-bit position error, as well as PID control engine with
acceleration and velocity limits for position control. A set of essential and
simple-to-use instructions is provided to control the motion application and
monitor ongoing performance.
Figure 1 – Elements of motion control
Host MK-200C Driver
Power
Supply
Motor
Encoder
RS
-
232C
PWM/Dir
CHA/
CHB

6
Features
Supports up to 2 axes
Configurable to support step or servo motors
5V tolerant PWM/Pulse and Direction outputs per axis to ensure
compatible with commercially-of-the-shelf amplifiers
Two channels (CHA and CHB) incremental encoder quadrature
input per axis
Two directional (Forward and Reverse) limits per axis
One home indicator per axis
One RS-232C interface port, configured at 115200 bps, to interface
with a host computer
Easy-to-use ASCII-based programming instructions
Small footprint (116.2 x 62.9 x 24.18 mm) with screw terminals for
ease of integration and maintenance
Lightweight with only 150 gram
+5 V operation and typical current consumption of 300 mA.
Figure 2 – The MK-200C 2-Axis Motion Controller

7
Related documents
•Command Reference.
•MOTKA Motion Companion User’s Manual.

8
2
2. . Getting Started
The terminal layout and definitions of MK-200C are shown in Figure 3 and
Table 1 respectively.
The instructions illustrated from Section 2.1 through Section 2.8 represent
a typical application.
Figure 3 - MK-200C
Gnd
Gnd
Gnd
CHA
CHB
HM
FL
RL
DIR
PWM
Fault
Gnd
PWM
+5V
Gnd
CHA
CHB
HM
FL
RL
DIR

9
Group Terminal
Name
Type
1
I/O Level
23
Function
Gnd P - Ground
CHA I FT Axis-A Encoder input CHA
CHB I FT Axis-A Encode input CHB
HM I FT,AL Axis-A Home indicator input
FL I FT,AL Axis-A Forward limit input
RL I FT,AL Axis-A Reverse limit input
DIR O FT Axis-A Direction output
AXIS A
PWM O FT Axis-A PWM output
Gnd P - Ground
CHA I FT Axis-B Encoder input CHA
CHB I FT Axis-B Encode input CHB
HM I FT,AL Axis-B Home indicator input
FL I FT,AL Axis-B Forward limit input
RL I FT,AL Axis-B Reverse limit input
DIR O FT Axis-B Direction output
AXIS B
PWM O FT Axis-B PWM output
AXIS A I FT,AL Axis A Stepper selectStepper
Select AXIS B I FT,AL Axis B Stepper select
+5V P - +5V supply
Gnd P - Ground
Power
In Fault I FT,AL Reserved. Do not use.
Rx - - Receive
Tx - - Transmit
RS-232
Gnd P - Ground
Table 1 – MK-200C terminal definitions
1
P = Power, I = Input, O = Output
2
FT = Five voltage Tolerant
3
AL = Active Low

10
2.1.Connecting the Power Supply
The MK-200C requires a +5 V operating voltage. It is highly recommended
to separate the power supply used for the MK-200C and the motor
amplifiers to eliminate noise interference.
Figure 4 – Power supply scheme
2.2.Connecting the Host
A host is required to drive the MK-200C through the RS-232C interface
with the following configurations:
Baud rate: 115200 bps
Data bit: 8
Stop bit: 1
Parity bit: None
Flow control: None
These configurations are not changeable.
The RS-232C interface can be connected directly to a host computer with
a RS-232C port (See Figure 5).
Power Supply MK-200C
+5V
Fault
Gnd
Gnd
+5V
Fault

11
Figure 5 – RS-232C-to-RS232C interface with host
2.3.Selecting Servo or Stepper
The MK-200C supports 2 axes, namely Axis A and Axis B. Each axis can
be configured to operate with a servo or stepper motor, depending on the
jumper, STEPPER SEL (Axis A and Axis B), setting. Inserting the jumper
configures the Axis to support stepper motor.
Both axes of MK-200 are, by default, configured to operate with stepper
motors with both jumpers inserted. If servo motors are used in an
application, simply remove the respective jumper. It is important to note
that the MK-200C reads these inputs only once upon power up. Any
change of configuration to these inputs will not be registered until
the next power up.
2.4.Connecting Servo Motor
MK-200C supports standard dc servo motor amplifiers operate with PWM
and Direction mode. It also supports standard 2-channel encoders with
CHA and CHB outputs. All PWM and Dir outputs, as well as CHA and
CHB inputs are 5 V tolerant. If amplifiers and encoders used in an
application utilise other operating voltage other than +5 V, level-shifter
must be used to match these voltages.
Host Computer MK-200C
Tx
Gnd
Rx
Tx
Rx
Gnd
2
3
5
3
2
5
RS-232C
RS-232C

12
Figure 6 and Figure 7 show the typical connections of a brushless and
brushed servo motor to an MK-200C’s axis respectively. The jumper of
STEPPER SEL for the respective axis must be removed.
Figure 6 – Connecting to a brushless servo motor to MK-200C
Motor A
Motor B
HALL 1
HALL 2
HALL 3
Motor C
MK-200C
Encoder
Brushless
Motor
CHA
Dir
PWM
CHA
Amplifier
B
A
Dir
PWM
CHB
Gnd
CHB
Gnd
(must have common ground)
C
HALL 2
HALL 1
HALL 3

13
Figure 7 – Connecting to a brushed servo motor to MK-200C
2.5.Connecting Stepper Motor
MK-200C supports standard stepper motor amplifiers operate with PWM
and Direction mode. When stepper operation is selected, MK-200 does
not support encoder inputs (CHA and CHB).
Figure 8 shows the typical connection of stepper motor to an MK-200C’s
axis. The jumper of STEPPER SEL for the respective axis must be
inserted.
Figure 8 – Connecting to a stepper motor to MK-200C
MK-200C Stepper
Motor
A+
Dir
PWM
Amplifier
A
-
A+
Dir
PWM
A
-
B+
B
-
B+
B
-
MK-200C
Encoder
Brushed
Motor
Motor+
CHA
Dir
PWM
CHA
Amplifier
M
-
M+
Dir
PWM
CHB
Gnd
Motor
-
CHB
Gnd
(must have common ground)

14
2.6.Connecting the Limits
There are two directional limits per axis, which can be used to prevent
collision due to over travelling. Leave these limits unconnected (inactive) if
we do not wish to use them.
Both Forward and Reverse limits are active low.
If the Forward Limit (FL) is active, it inhibits the forward motion
immediately. If the Reverse Limit (RL) is active, it inhibits the reverse
motion immediately. After a limit has been activated, further motion in the
direction of the limit will not be possible until the state of the limit returns
back to inactive state. This usually involves physically moving the
mechanisms or moving the motor in the opposite direction via instruction
set.
Figure 9 depicts the connection of standard slot sensors to these limits.

15
Figure 9 – Connecting to forward and reverse limits to MK-200C
2.7.Connecting the Home Indicator
The MK-200C comes with one Home indicator (HM) per axis. Home
indicators are designed to provide mechanical reference points for a
motion control application. A transition in the state of the home indicator
alerts the controller that a reference point is reached by a moving part in a
motion control system.
These inputs are active low and can be used with external sensors, such
as slot sensor, as depicted in Figure 10.
Home operation is initiated by the Move Home (MH) instruction. MH
instruction accepts both direction and speed of search. Refer to Command
Reference for more information.
MK-200C
FL
Gnd
+5V
10K
10K
RL
10K
+5V
10K

16
Move Home instruction initiates the corresponding PWM pulses and
Direction bit. In the example shown Figure 11, the MH instruction searches
in the forward (DIR is logic ‘0’) direction. Once the HM input is active (logic
‘0’), it toggles the Direction bit and reduces the speed of search, and
hence reverses the motion at a lower speed. This motion continues until
the HM input is inactive and the home operation is complete.
Figure 10 – Connecting to home indicator
Figure 11 – Home operation
2.8.Testing Our Connections
Having connected all the necessary circuitry described in the above
sections, we can start testing our application by sending a couple of
MK-200C
HM
Gnd
+5V
10K
10K
PWM
DIR
HM
Home sensor
active
Forward home search Home operation completes

17
instructions. To do that, we can use the MOTKA Motion Companion
software or any third party software that can send and receive ASCII
characters such as Microsoft HyperTerminal.
In the example below, we assume a servo motor is connected to Axis A.
For more information to tailor your instructions to suit your tests, please
refer to the Command Reference for complete set of instructions and
explanations.
The first instruction is to check for Motor Type (MT). The response of ‘1’
indicate that MK-200C is configured Axis A to operate in servo mode. Next
we disable Acceleration Limit (AL) by setting it to zero. Before we can
move the motor, it must be enabled by sending the Servo Enable (SE)
instruction to Axis A. We get the first position (GP) and MK-200C
responses with zero. We move the motor by 10,000 counts relative to
current position. Depending on the tuning of PID parameters (KP, KI and
KD) with respect to the loads, the response of the final position obtained
by GP may be different from the example below.
MT ?
1
AL 0
SE T
GP ?
0
MR 10000
GP ?
10003
2.9.Design Examples
Here are a few simple C/C++ examples for using your controller. You may
use other languages to send the ASCII commands via the serial port.

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Example 1 – Tuning of Controller
This example assigns the PID parameters to Axis A and read back for
confirmation.
CSerial port;
If(port.open(2, 115200)) // Open serial port and configured
{ // to baud 115200 bps
char Kp[7] = “KP 100”; // Set Proportional gain for Axis A
Kp[6] = 0x0D; // Terminate it with a Carriage Return
char Ki[7] = “KI 800”; // Set Integral gain for Axis A
Ki[6] = 0x0D; // Terminate it with a Carriage Return
char Kd[5] = “KD 2”; // Set Differential gain for Axis A
Kd[4] = 0x0D; // Terminate it with a Carriage Return
char query[5] = “KP ?”; // Query for KP
query[4] = 0x0D; // Terminate it with a Carriage Return
char readBuf[10]; // Container for reply
port.send(Kp, sizeof(Kp)); // Send KP to controller
port.send(Ki, sizeof(Ki)); // Send KI to controller
port.send(Kd, sizeof(Kd)); // Send KD to controller
port.send(query, sizeof(query)); // Query for KP
port.read(readBuf, sizeof(readBuf)); // KP is stored in readBuf
}
Example 2 – Profiled Move
In this example, Axis B moves a distance of 50,000 counts at the speed of
30,000 counts/sec and an acceleration and deceleration of 100,000
counts/sec
2
. It motor stops once it reaches 50,000 counts.
CSerial port;
If(port.open(2, 115200)) // Open serial port and configured
{ // to baud 115200 bps
char SE[6] = “SE, T”; // Servo enable for Axis B

19
SL[5] = 0x0D; // Terminate with Carriage Return
char SL[10] = “SL, 30000”; // Speed limit
SL[9] = 0x0D; // Terminate with Carriage Return
char AL[11] = “AL, 100000”; // Acceleration limit
AL[10] = 0x0D; // Terminate with Carriage Return
char DL[11] = “DL, 100000”; // Deceleration limit
DL[10] = 0x0D; // Terminate with Carriage Return
char MR[10] = “MR, 50000”; // Move Relative
MR[9] = 0x0D; // Terminate with Carriage Return
port.send(SL, sizeof(SL)); // Set speed limit
port.send(AL, sizeof(AL)); // Set acceleration limit
port.send(DL, sizeof(DL)); // Set deceleration limit
port.send(SE, sizeof(SE)); // Enable motor
port.send(MR, sizeof(MR)); // Move motor
}
Example 3 – Profiled Move of Multiple Axes
In this example, both Axis A and B move independently at the same time.
CSerial port;
If(port.open(2, 115200)) // Open serial port and configured
{ // to baud 115200 bps
char SE[8] = “SE T, T”; // Servo enable for Axis A and B
SL[7] = 0x0D; // Terminate with Carriage Return
char SL[15] = “SL 30000, 5000”; // Speed limits
SL[14] = 0x0D; // Terminate with Carriage Return
char AL[17] = “AL 100000, 80000”; // Acceleration limits
AL[16] = 0x0D; // Terminate with Carriage Return
char DL[17] = “DL 100000, 10000”; // Deceleration limits
DL[16] = 0x0D; // Terminate with Carriage Return
char MR[16] = “MR 50000, 75000”; // Move Relative
MR[15] = 0x0D; // Terminate with Carriage Return
port.send(SL, sizeof(SL)); // Set speed limits
port.send(AL, sizeof(AL)); // Set acceleration limits
port.send(DL, sizeof(DL)); // Set deceleration limits
port.send(SE, sizeof(SE)); // Enable motors

20
port.send(MR, sizeof(MR)); // Move motors
}
Example 4 – Reading of Position
The position of any axis can be queried with the GP instruction.
CSerial port;
If(port.open(2, 115200)) // Open serial port and configured
{ // to baud 115200 bps
char query[7] = “GP ?,?”; // Get position – A and B axes
query[6] = 0x0D; // Terminate with Carriage Return
char readBuf[10]; // Container for reply
char posA[5]; // Buffer for Axis A position
char posB[5]; // Buffer for Axis B position
int i = 0;
port.send(query, sizeof(query)); // Query for position
// Once controller received the command, it will reply the positions.
port.read(readBuf, sizeof(readBuf)); // Read the positions
// Positions replied contained in readBuf are separated by 0x0D
// Read position of Axis A
while(readBuf[i] != 0x0D)
{
posA[i] = readBuf[i];
i++;
}
// Read position of Axis B
while(readBuf[i] != 0x0D)
{
posB[i] = readBuf[i];
i++;
}
}
Example 5 – Velocity Control
In this example, we drive A and B motors at a desired speed.