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© 2005 Bob Campbell Designs
Design by Digital Platinum

Breakout Board Plus
for Mach2 and Mach3

The PC parallel port break-out board was developed by James Cullins.  James is the owner of Sound Logic in Grapevine Texas. The picture is of Rev level 1.8A.

The question that I get asked once in awhile is: Why do I need a break-out board? The options are, solder directly to a DB25 connector. I have done this and it creates a lot of wiring that is hard to manage. The next option is to buy a DB25 to terminal strip converter board ($35 to $45). The converter board is a lot better than soldering directly to a DB 25 connector.

Both option have their drawbacks which are addressed with the features in a break-out board.

The first and very important feature is isolation. The break-out board provides total optical isolation of the parallel port from the power supply and the equipment being controlled. If  high voltage is inadvertently applied to any lead on the parallel, it most likely will burn out something inside the PC.  With the break-out board, the parallel port is isolated. Voltage can burn out parts in the break-out board, which can be replaced.

The break-out board was designed to interface to the Gecko drives and inductive proximity sensors or standard micro switches. In the case of the Gecko drives, the board provides the 5 volts  needed to power the optical isolators in the Gecko drives. The board also has a switch that will allow it to interface to other drives that want the ground connected to the PC ground.

The break-out board has screw terminal for all signals. In most cases, a led is also present on most lines.

The break-out board contains three power supplies. One 5 volt supply is used to provide 5 volts to power the optical isolators in the Gecko drives. A 12 volt power supply  is provided to supply power to the proximity sensors. A second 5 volt supply is provided to convert the output from the proximity sensors back to 5 volts before it is sent back to the PC.

The input connector is a 26 pin duel in-line connector.  The 26 pin connector is connected (ribbon cable) to a 25 pin parallel port connector which would mount on the outside of your control box.


Mach2/3 feature

The PC parallel port will set some of the output pins (pin 1, 14 ,16 and 17) high when you power it up. This could cause serious injuries if the external devices are left on. To prevent this Mach1 can be setup to output pulses at about 15khz . A circuit has been  designed  to monitor pin 17 and will enable the output circuits for the relays. This prevents the external devices like the spindle, vacuum pump, or coolants pumps from being turned on when the PC is powered on. To take advantage of the feature set jumper JP3 to M1 then set Mach1 up to output the 15khz to pin 17 (IO-4). You do sacrifice one output #4 . That output can be used to turn on the power supply to the motor drives or just as an indicator that Mach1 is up and working.

The cost of the Mach2 board is $130 (new temporary price $99.00). For this application the board replaces multiple items that would be required to provide the same functions at a much higher cost. I am currently shipping a ribbon cable (DB25 on one end and an inline connector on the other end) with each board.

For ordering and additional information, click here.

To download the General User's Guide, Rev 1.7 click here.

oT download the General User's Guide, Rev 1.8 click here.


"Creative people inspire the rest"

© 2005 Bob Campbell Designs
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