myCNC-ET7 controller board

myCNC-ET7 controller specification

Number of motor outputs


Motor driver outputs

differential line driver outputs compatible with EIA RS-422 Standard

Maximum pulse frequency

3 MHz

Binary inputs

16x galvanic isolation,
PNP/NPN sensor compatible

Encoder inputs

3x incremental encoder inputs,
differential line driver (EIA RS422 compatible),
hardware decoded, 5MHz max frequency

Binary outputs

5x - pluggable relays 10A, NO/NC contacts
11x - open collector, 24V, 0.25A

PWM outputs

3x - open collector, 24V, 0.25A,

ADC inputs

2x - 0...10V range, differential inputs, fully galvanic isolated
(for plasma arc voltage measure, THC control),
6x - 0...3V range

DAC output

1x - 0...10V (for spindle speed control and relative applications)


1x RS422 full duplex serial communication
2x RS485 half-duplex serial communication

External operator panel connector

up to 25 external keys
up to 2 rotary encodersup to 2 double-axes joysticks OR
up to 4 potentiometers (shared with 4x ADC inputs)

Power supply outputs for control computer

2x DC-DC converters 5V 1.5A


Please find the full ET7 control board connectors descriptions on our online documentation website


Power Supply Connections

myCNC-ET7 control board uses 24VDC . The board contains 4 pins for connection +24V (joined internally) and a number of GND pins for convenient connection of external devices. Power Supply 24V DC and +24V and GND pins are shown on a picture below.

myCNC-ET7 board contains 2 independent 5V 2A step-down converters which can be used to supply a Single board Computer (SBC) and TFT screen to build a complete standalone CNC control.

The built-in power supply  connector shown in the picture above has the  +5V and +12V outputs as well as 2 GND pins.


ET7 Output pins

ET7 board contains 19 output pins:

  • 5 relay outputs (OUT#11 ... OUT#15)
  • 11 open collector outputs (OUT#0 ... OUT#10)
  • 3 PWM outputs (PWM#1, PWM#2, PWM#3)
<code>WARNING: ET7 board rev.1,2 has Output pin names printed on Bottom side of the board.
These names are NOT correct and differ from actual output addresses.
Please check the table below to find out the actual output address</code>


SILK print Actual Output Pin Address
P0A OUT11 (A)
P0B OUT11 (B)
P0C OUT11 (C)
P1A OUT12 (A)
P1B OUT12 (B)
P1C OUT12 (C)
P2A OUT13 (A)
P2B OUT13 (B)
P2C OUT13 (C)
P3A OUT14 (A)
P3B OUT14 (B)
P31 OUT14 (C)
P4A OUT15 (A)
P4B OUT15 (B)

OUT15 (C)


Schematic for ET7 inputs & outputs is shown below:


Pulse-Dir outputs

ET7 has 6 channel pulse-dir outputs, with a max pulse frequency of 3MHz.

ET7 pulse-dir outputs conform to the RS422 standard and are compatible with most of servo and stepper drivers (line driver with paraphase signals of positive and negative polarity). Internal schematic for pulse-dir is shown on a picture below.

The pulse/dir schematic is shown below:

Optional Operator panel board for ET7

myCNC-ET7 control board supports an external operator panel which may contain up to 25 keys (in a 5x5 matrix matrix), 2x rotary encoders and up to 2x double-axes joysticks or 4 potentiometers to control CNC parameters. Functions can be flexibly assigned to any key, resistor, joystick, or encoder.

Suggested schematic for an external operator panel is shown below.


ET7 external operator panel suggested schematics


 External operator panel is connected to ET7 board via a connector. The connector pinout is shown in the picture below.


Optional Operator Panel board ET7-KEY-001 is available for the ET7 controller.

Operator panel board for ET7

We can offer custom design Operator Panel Boards according to the particular requirements and specifications. Approximate price is $35/pcs if ordered with ET7 controller board (MOQ is 10pcs)


Open collector Binary outputs & PWN outputs

ET7 contains 11 open collectror outputs and 3 PWM outputs. Output circuit is based on the Darlington ULN2003 transistor array. According to chip datasheet, each output is capablle to drive up to 500mA, however we recommend to not exceed 250mA.


Binary inputs

ET7 contains 4 blocks of 4 binary inputs per each block. 4 opto-couple LEDs within the block have a common line. Common line of each block is isolated from the other blocks. This makes it possible to use different power supplies or mixed PNP and NPN sensors with different blocks.

Each common line can be shorted to GND by closing the jumper switch, If the internal 24V DC power line is used to supply the sensors.

Schematic design of the input block is shown below:




Connection Examples


3-wire NPN sensor connection example (external power supply)

Jumpers J1,J2,J3,J4 are all open.

3-wire PNP sensor connection example (external power supply)

Jumpers J1,J2,J3,J4 are all open.

3-wire NPN sensor connection example (internal power supply)

Internal power supply.
One of jumpers J1,J2,J3,J4 (J4 in case of this example) is closed.

3-wire PNP sensor connection example (internal power supply)

Internal power supply.
All of jumpers J1,J2,J3,J4 are open.

As the sensor requires a 24V power supply, it is necessary to connect it to the 24V port, not the 5V.

Switch connection example (internal power supply)

Jumper for selected group (one of J1,J2,J3,J4) is closed.

Common wire for 4 optocouple units is connected to internal +24V if Jumper is closed. Switch should short another optocouple input to GND (0V) to activate input pin.

J(#) - in this case, J4 - should be closed to connect optocouple pin to +24V. Switch should also short the wire to GNC(0V).

Switch connection example (external power supply)

Jumpers J1, J2, J3, J4 are all open



Control computer for myCNC-ET7

myCNC-ET7 board works under control of myCNC software. Control computer needs to build a complete CNC control system based on myCNC. It can either be a standard desktop/industrial computer with Linux or MS Windows OS installed
a small single board computer like the Odroid-C2, Odroid-XU4, or a Raspberry-Pi3/Pi2


myCNC-ET7 board contains a built-in DC-DC converter and mounting holes to install and power-up the Odroid/Raspberry computer board.


ET7 with Odroid-C2 computer mounted


A standard monitor with an HDMI port can be connected to the Odroid-C2 computer board. Screen resolution up to 1920x1080 (Full HD) is supported.  Fully functional Ubuntu 16.04 Linux and myCNC control software can be installed on the computer. NC code files can be uploaded to the computer through Wifi (Samba Server, FTP Server installed on the computer) or USB disks.

We can offer affordable 10"/15.6" screens with resistive touch to build a complete stand-alone CNC control kit.




myCNC-ET7 connection examples.






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