C79- EXPANSION BOARD Rev. 2

APRIL, 2025

1.0 OVERVIEW

This card provides an easy way to connect your inputs and outputs from your port using a LPH26pin Ribbon Cable or parallel port. Provides terminals for connections and conditions signals for use in CNC applications; this version can be easily mounted on control boxes using DIN rails and can also accommodate ribbon cables or DB25 connectors.

2.0 FEATURES

Terminal Block for all I/Os.
Buffered outputs.
Open collector Outputs, Pins optoisolated 1, 14, 16, 17.
Compatibility with several Motion Controllers and motherboards. C76, M16D, UC300ETH-5LPT, C92, and ESS expansion board.
Input pins 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15.
Terminal Block input with close-by ground or +5vdc connections, COM, and outputs with + 24vdc and ground
Screw-On connections for all terminals. You only have to screw-on the wires to make all your connections.
Status LEDs for enabling.
Fully Optoisolated Inputs and Outputs.
External Enable Pin
Din rail mountable.
Pluggable Screw-On Terminals.

3.0 SPECIFICATIONS

DIGITAL INPUT SPECIFICATIONS
On-state voltage range	24V DC
Maximum off-state voltage	0.8V
Maximum operation frequency	4 MHz
Typical signal delay	10nS

OPEN COLLECTOR OUTPUT SPECIFICATIONS
Maximum output voltage	60VDC
Maximum output current	2Amps
Typical signal delay	0.5 µS

4.0 BOARD DESCRIPTION

5.0 REQUIREMENTS

5.1 Power Requirements

Regulated +5VDC, which can be supplied through pin 26. +12 or 24VDC is required to power the Open Collector Outputs and Optoisolated Inputs.

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The +5vdc can be supplied through pin 26 on the IDC26. If supplying +5vdc through the IDC26, do not apply +5vdc externally as it will damage the board.

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Check the polarity and voltage of the external power source and connect the 5VDC and GND. Overvoltage or reverse-polarity power applied to these terminals can cause damage to the board, and/or the power source.

6.0 POWER TERMINAL

To preserve optoisolation two independent power sources should be used.

A +5Vdc to power the logic and optos that interact with the controller. Since these are isolated, they can come from a USB cable or pin 26 on the IDC26 connector. The +12/24VDC at 200 Amp will power the Open Collector Outputs and Inputs.

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The +5vdc can be supplied through pin 26 on the IDC26. If supplying +5vdc through the IDC26, do not apply +5vdc externally as it will damage the board.

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This board uses pins 2-9 as inputs. It must be connected to a controller that uses pins 2-9 as inputs. If using the Ethernet Smooth Stepper, make sure to configure it to use pins 2-9 as inputs before wiring it.

6.1 Enable pin.

The card must be provided with a 24VDC signal to enable operation. This feature has been added to externally control the status of the outputs. An external switch or a Safety Charge Pump can be added to provide the enabling signal. If this function is not required, a jumper can be placed between 24VDC and the EN terminal.

If using it with the C76 or M16D using an IDC26 to IDC26 ribbon cable, you can leave a jumper on the EN terminal and allow the motherboard to control the enable. The C79 will be enabled when the motherboard is enabled. This is done through pin 18 of the IDC26 connector.

7.0 INDICATOR LED

The power LED lights indicate that the system is ready but disabled. When Status LED, (Green LED) lights, it indicates that the system is enabled.

8.0 PINOUT

8.1 Pin numbering

8.2 IDC26

IDC26 Pin number	LPT port direction signal
1	Output 1
2	Input 2
3	Input 3
4	Input 4
5	Input 5
6	Input 6
7	Input 7
8	Input 8
9	Input 9
10	Input 10
11	Input 11
12	Input 12
13	Input 13
14	Output 14
15	Input 15
16	Output 16
17	Output 17
18	Watchdog (Ground to Enable)
19 - 25	GND
26	+5VDC

8.3 Compatibility

CONTROLLERS	PORTS
C76	3
M16D	3
ESS	2
5LPT	1, 4, 5
C92	1,2,3

9.0 CONFIGURATION SWITCHES

9.1 Connecting Switches Using the COM = GND

There is a jumper that allows you to select +12/24VDC or GND for the COM pins.

While this board supports input +24VDC signals, different kind of sensors, switches using different voltages can be connected using the diagrams that follow:

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This board has two possible inputs banks, (pins: 10, 11, 12, 13, and 15 or 2-9) and (dedicated outputs: pins 1, 14, 16, and 17), and all the inputs of the same bank have the same configuration. The below wiring diagrams are an example, any input can be used for the connections.

Fig. 1 Wiring diagram to connect switches.

9.2 Connecting Switches Using the COM = 12/24VDC

Fig. 2 Wiring diagram to connect switches.

10.0 EXAMPLE WIRING OPTOISOLATED OUTPUT

The power source of 12/24 VDC is for the correct functioning of the outputs (1,14,16,17).

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The +5vdc can be supplied through pin 26 on the IDC26. If supplying +5vdc through the IDC26, do not apply +5vdc externally as it will damage the board.

11.0 WIRING DIAGRAM SENSORS

11.1 Connecting PNP sensors.

Fig. 3 Wiring diagram to connect PNP open collector proximity sensors.

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The +5vdc can be supplied through pin 26 on the IDC26. If supplying +5vdc through the IDC26, do not apply +5vdc externally as it will damage the board.

11.2 Connecting NPN sensors.

Fig. 4 Wiring diagram to connect in parallel NPN open collector proximity sensors.

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The +5vdc can be supplied through pin 26 on the IDC26. If supplying +5vdc through the IDC26, do not apply +5vdc externally as it will damage the board.

12.0 DIMENSIONS

All dimensions are in Millimeters.

Fixing holes (4mm).

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DISCLAIMER

Use caution. CNC machines can be dangerous. Neither IGNATE, LLC, nor Arturo Duncan is liable for any accidents resulting from the improper use of these devices. This product is not a fail-safe device, and it should not be used in life support systems or in other devices where its failure or possible erratic operation could cause property damage, bodily injury, or loss of life.