C1-PARALLEL PORT INTERFACE CARD Rev5

Overview.
This card has been designed to provide a flexible interface for CNC projects using parallel port control software. Proven implementation of buffering and optoisolation circuits provides for a quick and reliable solution.

Features

• Fully optoisolated 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. In that way, your computer’s electronics are completely isolated from the cnc circuitry. 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.

• Buffered outputs. All inputs and outputs are buffered through the use of high speed and high power buffers. Each pins deliver 24 milliamps.

• The common terminal to pins 2-9 can be ground or +5vdc. The board has a jumper that allows you to select if the common terminal to pins 2-9 will carry a ground or +5vdc. So if you are connecting encoders or proximity switches, you can select it to ground. If you are connecting Geckodrives or limit switches, you can set it to be +5vdc.

• All pins can be used in a concurrent manner. You can use all the input or output pins in a concurrent manner. For example, if you are using output pin #1 to control the Built-in Solid State Relay Board, you can also access that signal from the output pin on the board or from the DB25 connector for output. Each connection will not affect the other current from the other connection.

• External Enable Pin (EN). The board has a pin that allows you enable/disable all the outputs at once. The board requires +5vdc in the EN pin. If it is not present, it will send all the outputs to ground immediately. You can use this enable and disable your system manually, or you can install an external Safety Charge Pump or other external device.

• Status LEDs on all inputs and output connections. No more guessing. You can SEE all your signals. Save valuable time and brainpower for cncing.

• Has an extra DB25 female connection for output. This card can be used to optoisolate any existing setup just by connecting this card between the computer and current control box. That way, you can also see and access all the signals. This makes the board ideal for use with the xylotex, hobbycnc or other non-optoisolated boards. You only have to add this board to a DB25 male connection to a male cable.

• All inputs are outputs are tied to pull-down resistors. Pins are never in the air open to noise. If you leave a pin in the air you will get a LOW or 0. If you input a ground you will get a LOW and a +3.3 or+ 5 vdc signal will deliver a HI.

• Works directly with popular CNC hardware and software. Such as Geckodrive, DeskCNC or Rutex, and parallel port control software, such as mach2, Linux EMC, TurboCNC, CNCPlayer, CNCZeus and others. (Not all tested)
 

 

BREAKOUT BOARD COMPARISON CHART

 

Check out the scope images at 93.9khz on pins 2-9.