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myCNC-ET7 CNC controller

ET7 top view


Power supply connection

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.


Pulse-Dir outputs

ET7 has 6 channel pulse/dir outputs, 3MHz max pulses frequency.

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

Pulse-dir schematic pulse-dir6.jpg


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)
WARNING: ET7 board rev.1,2 has Output pin names printed on Bottom side
of the board. This names are NOT correct and differ from actual 
output addresses. Please check the table below to find out 
actual output address
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)
P41 OUT15(C)

Schematic for ET7 inputs & outputs is shown below


Galvanic isolated inputs

ET7 control board has 16 galvanic isolated binary inputs, 4 groups of 4 inputs each. Each group has separate power supply pins so inputs can be powered from different power sources. Using PNP and NPN sensors simultaneously is possible too.

Galvanic isolated inputs schematic is shown below

Connectors pinout for binary inputs is shown on a picture


Encoder Inputs

ET7 control board has 3 AB incremental encoder inputs with hardware implemented decoding. Max pulse frewuency of encoder pulses is 3MHz. 6 encoder input signals are mapped to General purpose binary input addresses 20…25 and gan be used as normal binary inputs. Encoder inputs are line driver differential signal compatible.

Encoder inputs schematic is shown below

Encoder inputs connector pinout is shown on a picture


ADC Inputs

myCNC-ET7 controller has 8 ADC inputs.

  • 6 ADC inputs 0-5V range
  • 2 ADC inputs with galvanic isolation for save and convenient connection of Arc Voltage signal from Power station. Galvanic isolated ADC inputs are 0..10V, so High Voltage Arc signal CANNOT be connected directly to ADC inputs, voltage divider is NEEDED.

0-5V ADC inputs schematic is shown below

Isolated ADC inputs schematic is shown below

Connectors pinout for ADC inputs is shown below

Non-isolated ADC inputs have 0…5V Range. Connector with non-isolated ADC inputs has also GND and +5V DC output pins for convenient potentiometer connection. Picture below shows an example for potentiometer connected to ADC2 input.

RS422/RS485 Bus

the myCNC-ET7 control board has RS422/RS485 bus connector. Modbus ASCII/RTU and Hypertherm Serial communication interfaces are implemented in the myCNC-ET7 control board.

RS485 bus enabled by default.

To enable RS422 intefrace you need

  • close jumper J__
  • setup RS422 inteface in the control software.

Please contact our support team if you need to use a RS422 bus.

A RS422/RS485 schematic is shown below

RS422 connector pinout shown below

DAC output

the myCNC-ET7 control board has DAC output for spindle speed control. DAC output range is 1..12V Actual Max DAC voltage (ie 10V, 5V, 6V) can be setup in the myCNC control software.

Connection Examples

3-wire NPN sensor connection example

Jumpers J1,J2,J3,J4 are open.

3-wire PNP sensor connection example

Jumpers J1,J2,J3,J4 are open.

Switch connection example

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.

J4 should be closed to connect optocouple pin to +24V. Switch should short wire to GNC(0V).

Spindle Speed control over DAC (0-10V) output

Board dimension

ET7 keypad board

We have a simple keypad board that can be used with the ET7 controller. Keypad board connected to an ET7 controller through 20 wires flat cable. Keypad contains 23 keys, 2x rotary encoders and double-axes simple resistive joystick.

ET7 control board interface to connect external keyboard is shown below

ET7 connector pinout


ET7 connector X4 pinout table

X4 connector to External 25-keys keyboard
Pin# Name Comments
1 OUT A Keyboard matrix output pins
2 OUT B Keyboard matrix output pins
3 OUT C Keyboard matrix output pins
4 OUT D Keyboard matrix output pins
5 OUT E Keyboard matrix output pins
6 IN #1 Keyboard matrix input pins
7 IN #2 Keyboard matrix input pins
8 IN #3 Keyboard matrix input pins
9 IN #4 Keyboard matrix input pins
10 IN #5 Keyboard matrix input pins
11 E#0 Encoder input (General purpose input)
12 E#1 Encoder input (General purpose input)
13 E#2 Encoder input (General purpose input)
14 E#3 Encoder input (General purpose input)
15 ADC _
16 ADC _
17 ADC _
18 ADC _
19 GND
20 5V



Each key, rotary encoder and the joystick functions can be programmed in configuration dialogs.

Schematics of the external ET7-KEY board is shown below

mycnc/mycnc_et7.txt · Last modified: 2018/08/14 12:12 by skirillov