Signal Consulting, LLC 

Model Si15NeUdMC1-30V-20A

RoHS Compliant Networkable, Unidirectional, Open-Loop, 30V 20A, Motor Controller with RS232 Serial Control Port, Display Port, Integrated Heat Sink and with 6.2kHz or 25kHz PWM, B-Chip





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 Si15NeUdMC1-30V-20A Features:
Power Semiconductors: Two 60A MOSFET
Max. Continuous Current: 20A with Heat Sink (as Shown)
Max.  Current for 5 sec: 40A with Heat Sink (as Shown)
Overall Dimensions: 61mm x 57mm x 44mm
Integrated Finned Heat Sink with 4-40 Standoffs and Screws   
Component Type: 100% Solid State,  RoHS Compliant RoHS Compliant

Control Inputs:  9600bps Networkable RS232 Control or Up/Down  Keys Control.    
RS232 Port for %PWM Display

Max. Continuous Current: 20A with Heat Sink (as Shown)

  Adjustable Load Voltage: The average Load-Voltage is adjustable from 0V to 30V in 0.83% steps ( or max. value of Vp) with a Pulse-Width Modulation (PWM) control signal.

  High Power-Efficiency: 97.5% typical, at 30V and 20A

On Board:
Filter Capacitors
VTS diodes
Snubber Circuit Ready
Load-Voltage Indicator, LED (red)

Voltage Requirement:
A single DC Source Voltage (unregulated and Unfiltered) with any voltage value from 9V to 30V (for Vp)


 Si15NeUdMC1-30V-20A-2B2   Spec Sheet  (PDF)

The Si15NeUdMC1-30V-20A is a 30V 20A, networkable, microprocessor based, high-power, Unidirectional, Motor Controller that uses a single (9V to 30V at 0 to 20A) DC power supply to control the speed of a DC motor in forward direction. An onboard microprocessor generates a 6.2kHz or 25kHz PWM carrier signal, controls the load-power (or motor speed), controls the load-current rate (or motor acceleration and deceleration), updates the display, monitors the user inputs and controls the RS232 Network Port. As the name (Ne, Networkable) implies, the %PWM (PWM pulse-duration) of the motor current is variable from 0 to +100% in 0.83% steps by using ASCII command strings on the RS232 Network Port; or it can changed by using external UP/DOWN keys connected to J2 and J3. The RS232 data format and the Local Area Network (LAN) commands are described on the next page. The PWM carrier frequency is selectable by the Dip-Switch S3, 6.2kHz when S3 is short and 25kHz when open. In addition, the user can choose between slow or fast motor acceleration/deceleration values using Dip-Switch S4. The fast-ramp, with rise-time/fall-time of 0.05s, is selected with S4 open; while slow-ramp, with rise-time/fall-time of 0.5s, is selected S4 closed. All control lines are sampled approximately at 20Hz rate in the fast mode (S4 open), and at 8Hz rate in the slow mode (S4 closed). An external Normally Open Switch or an Open Collector NPN transistor can be connected to J1 port to disable the load current (J1 Open=Run, J1 Short=Stop). The active pin of J1 is internally connected to +5V using a 4.7k Ohm resistor (as shown on the diagram below).The Jumper and Dip-Switch selection tables are shown below.  A red LED is used to monitor the motor (or load) voltage. A 9600 Baud serial port (CN4) with 5V RS232 Interface standard is provided to display of the Motor Speed data on an optional Si14LCD2L16CH-3PC LCD using a 2-Line by 16-Character format (described below). A small (2.4”x2.3”x0.5”), integrated Aluminum heat-sink is used to operate at 20A current levels. Higher current-levels (25A or 1200W) can be achieved with more efficient heat-sinks. Please click on this link and read the Board Mounting Instructions and Heat Sink Selection Guide. This board operates in a wide voltage-range (9V to 30V) at max. continuous load-current of 20A.Typical applications are: Unidirectional DC Motor-Speed Controller, Flicker-free LED light intensity control, Proportional Valve-Coil Controller, etc. This board can be configured and programmed to perform efficiently in many customized applications.

                                                             Dip-Switch Selection Table

   S4 Open = Fast Ramp Time,  0.05 sec

   S4 Short = Slow Ramp Time, 0. 5 sec

   S3 Open = 25kHz PWM Frequency

   S3 Short  = 6.2kHz PWM Frequency 

                                                              Jumper Selection Table

J1 Open = Motor Runs With PWM

J1 Short= Motor Stops

J2 Open = Normal Networkable Operation

J2 Short= Increment Set RPM

J3 Open = Normal Networkable Operation

J3 Short= Decrement Set RPM

Note: The Jumpers J1, J2, J3 are examined at each sampling period (loop-time).  While the Dip-Switches S4 and S3 are examined only at power turn-on.

A Typical Application of the Si15NeUdMC1-30V-20A

 In this open-loop application, the PWM or motor speed is adjusted by command strings derived from a Personal Computer (PC) using the Microsoft “Hyper Terminal” program (or any-other ASCII controller) operating at 9600 Baud, 1 start-bit, 8 data-bits, 1 stop-bit, No parity-bit.  In addition, the PWM can be adjusted with Up/Down Keys (Si15PB2-MC4 ) connected to pins J2 and J3.  An optional serial LCD module Si14LCD2L16CH-3PC  (2-Line by 16-character LCD with back light and 12” cable) can be connected port CN4 to display the set and measured %PWM values. Warning:  The connecting wires to the Load and the Power Supply must be heavy gauge copper wire (#12 AWG or heavier) to handle the rated current level. In addition, these heavy gauge wires act as a heat sink, protecting the board from overheating.

Command Format and Local Area Network (LAN) for the Si15NeUdMC1-30V-20A

Each board has a unique, 8-bit, ASCII, none-volatile, Node-Address ranging from 1….9, A..Z, a,…z ( or a total of 61 Units can be networked).The address can be changed by a LAN command (the factory default address is 1). The board uses a modified version of the RS232 serial-data communication standard, where the output-voltage (on pin I2, CN5) ranges from 0 to +5V (rather than the usual -12V to +12V). In addition, this output pin is normally an open circuit and it will only output a serial TTL binary bit-stream when properly referenced by its Node-Address. The serial data input-voltage (on pin I1, CN5) has the standard range of -12V to +12V. The serial data-format is: 9600 Baud Rate, 1 Start-Bit, 8 Data-Bits, 1 Stop-Bit, and no Parity-Bit.

These features allow the creation of a Local Area Network (LAN) with up to 61 nodes (boards). A typical 3-wire LAN with “Star Topology” is shown below. Note that the control lines (G, I1, I2) with the same name are connected together (or the boards are connected in parallel) and driven by an ASCII controller (or PC), equipped with an RS232 serial port, operating at 9600 Baud rate.

Command Rules:

1.  All Commands are ASCII character strings (Chars.).  An ASCII string is denoted here with Bold Red Letters (Characters).

2.  Each string is terminated by a Carriage Return Character, (CR). The only exception is the # command.

3.  Upper-Case Letters are used for Output Commands; and Lower-Case Letters are used for Input Commands.

4. The 1st Char. in a string is either ASCII # or a Node Address (1, .,9,A..Z, a,..,z). If the 1st Char. is an #, it denotes a query to all boards on the LAN to output their Node Address and Program Name.

5. If the 1st Char. is an ASCII (1..,9,A,..Z, a,…,z), it directs the rest of the command string to the board that has this address.

6. The 2nd Char. in the string is the Command Character that operates on the addressed board.

7. The 3rd, 4th, 5th Chars. represents the value of the input data.

8. The last Char. in the sequence is always the string terminator, (CR).

Command Examples:

Ex#1.  Com. String:  #   Action: All boards on the LAN will output their Address and Program Name.

Ex#2.  Com. String:  1u5(CR)      Action: Change Board 1 Address in EPROM from 1 to 5.

Ex#3.  Com. String:  1M(CR)       Action:  Board 1 outputs its Set and Measured Values (0,..120).  

Ex#4. Com. String:   1m120(CR)    Action: Change Board 1 Load Value to 120 = 100% PWM.

Ex#5.  Com. String:  2m60(CR)     Action: Change Board 2 Motor Value to 60 = 50% PWM.

We recommend that you use approximately 25msec (or longer) delays between characters when inputting a command string (“1m..(CR)”, “1M(CR)”) to this controller board. Occasionally, a transient character may be captured and buffered by one more board on the LAN, this transient character can be cleared by sending one  or more (CR) prior to a valid command string.

Note1: The m command inputs decimal integer Motor Values, ranging from 0,….+120. The positive values are used for forward speed control. The PWM duty-cycle varies linearly with the input values; 0 value is equal to 0% PWM, while 120 value is equal to 100% PWM.

Note2: The m command is NOT subject to round-off” errors!!!

Note3: The last set value entered with the m command or with the Up/Down keys is saved when the power is turned off, and this value is restored when the power is turned back on.

Response to Commands on Output Line I2:

The response to a "1M(CR)" command is an ASCII character string (or a line of characters). Each string is terminated with carriage return and line feed characters. An example is shown below:

 N=1  SM=120  MM=120

 Note that there are two space characters between 1 and S; and there are two space characters between 0 and M. The length of this character string is 22 characters, including carriage return and line feed (not shown in this example).

 Where N=1 is the node (or unit) address of the board (can be changed with the u command), SM=120 is the last Set-Motor Speed Value (entered with the m command), and MM=120 is the current Measured-Motor Speed Value.

  Each character string (line) is a continuous stream of ASCII characters with an occasional pause (or delay) between characters. This delay is approximately 1msec.

CN4 Display Format:

A 9600 Baud serial port (CN4) with 5V RS232 Interface standard is provided for optional display of the %PWM Motor-Current data.

 Si14LCD2L16CH-3PC  2-Line by 16-Character LCD on Port CN4 with Display Format:

 Line#1:    SM=120    MM=120         or Measured Motor-Current PWM is 100%.

 Line#2:    N=1   B=xxxxxxxxx         or N=Node Address,   B= Commands Entered.

 For more information on Displays, please click on these links: (Si14LCD2L16CH-3PC , Si4Display-Spec1).

Network Configuration:

The on-board microprocessor provides the bus arbitration, required to avoid data collisions on the 3-wire LAN bus. The  Si..Ne.. boards can be arranged in many Local Area Network (LAN)  topologies: Star, Daisy-Chain, etc.  You may create your own network or you may order one or more of the Network Cable Assemblies listed in the Application Note.   Before you build your network, click on this blue link and read this Application Note:  SigNote on Configuring a LAN-2.


Si15NeUdMC1-30V-20A  Networkable Unidirectional Motor Controller
Price $159.00

Note: If Buying the Si15NeUdMC1-30V-20A, it is recommended to buy Optional:  one Display, one Up/Down Keys and some Network Accessories.

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