IEEE 1284 Standard compatible.  Includes the circuitry recommended by the IEEE 1284 Level 1 standards for bidirectional parallel communications between personal computers and peripherals

PULL-UP or PULL-DOWN selection for inputs.  Includes jumpers to select the best input configuration for your application. 

Fully optosiolated. The card isolates connections to protect your computer from short-circuit. An opto-isolator is an integrated circuit that transmits the signal through an encapsulated LED and phototransistor. When the signal is on, the LED lights up, the phototransistor captures it and relays the signal. The signals are transmitted through light and not through physical connections. In this way, a power surge has no way of reaching your computer. That is the reason why this card has two power connections. One power connection is power powering the circuit that interacts with the PC; the other connection is for powering the circuit that interacts with your CNC system. Extra precautions have been taken when designing this circuit, by taking into consideration the extremely high voltages that stepper drivers can achieve and lack of experience that some users could have in wiring circuits of this kind. This board keeps the grounds of the PC isolated from the grounds of the rest of your CNC circuit.

Support for up to 150 KHz optoisolation on step and direction signals. New on this revision is that the optoisolation circuit has been optimized and now supports full optoisolation at speeds over 150 kHz. 

Built-in Passive Low Pass Filters for the all signal.  This board includes low pass filters to reduce the effect of the noise from the drivers or other devices over the signals.

Microcontroller based SCHP. This board comes with a microcontroller that allows the implementation of a complex algorithm for sampling and analyzing the SCHP signal. 

All TTL 5VDC signals.  Interface directly with parallel port interface products and other CNC4PC cards. 5VDC (TTL) cards are very common among automation devices.

Buffered outputs.  All outputs are buffered through the use of high speed and high current buffers, with the result that your devices receive all the power they need. 

Easy installation of an On/Off switch. You can control the card externally.  An On/Off or a Safety Charge Pump can easily be installed to enable or disable the card. CNC machines could be dangerous and, remember, safety comes first. This card is provided with an extra pin (EN) that allows you to control the card externally by enabling or disabling outputs. The card must have +5vdc supplied to the EN terminal to enable outputs.

Status LEDs on all inputs and output connections.  No more guessing. You can SEE all your signals. Save valuable time and brainpower for CNC ing. To avoid remaining current to the main load (driver or other device), all the indicator LEDs are driven by independent buffers of the ones that drive de output. 

Built-in Variable Speed Control.  It has an optoisolated analog 0-10VDC output that will convert a PWM signal into an analog signal that can be used to command a commercial VFD. This analog can be adjusted using on-board potentiometer, so this board can be adjusted to other voltages. 

3 Built-in Electromechanical Relays with NO and NC positions. 

Input and output pins with close by ground connections.  Forget about grounding problems. Easily connect your pin by using your close by ground connection. No need to be an electronics expert to ground all your stuff. The terminals next to pins 2-9 can be set to have +5VDC or GND according to your needs. There is a jumper that allows you to select +5VDC or GND for the COM pins. 

Works directly with popular CNC hardware and software.  That goes for Geckdrive, DeskCNC or Rutex and parallel port control software such as mach2, Linux EMC, Turbo CNC, CNC Zeus and other/ (Not all have been tested). 

Screw-On connections for all terminals.  You only have to screw-on the wires to make all your connections.