The new MINI-IO-2 is the same small footprint, low priced, powered breakout card as its forerunner MINI-IO, but with a few enhancements:
Expanded low cost plug-in options (Relay Card, Activity Monitor, Port 2 Card)
On-board dual split power supply
TRUE optoisolation on inputs (separate grounds)
4 Axis of outputs 4 aux buffered outputs
Open collector outputs to drive magnetic relays
Now available with 220VAC input option
Direct Xylotex connector
Included Charge Pump Safety Circuit
$64.00 with Charge Pump, Support CD with MACH3 files, Printed Manual and DB25 Port cable.
Find out how affordable a quality interface can be.
Thanks for the info. I was (incorrectly) thinking that these would drive the motors, and was wondering how it was done with that small transformer. This looks like it would have been a good solution for a problem I had on my homebuilt L297/298 driver board where ground noise from the motor driver was getting back into the logic and causing uncommanded stepping.
The parallel ports on most computers are not designed to drive low impedence loads or turn on LED's, relays,etc. Some newer ports only swing to +3.3VDC which is not enough for some motor drive inputs.
Grounding between the logic side and the power side can be tricky. Any length over a few inches becomes a noise conductor.
As a Power Design Engineer in the Linear and Switching end of things I learned how subtle noise can be and how painful it can be to trace and cure without the right tools. When it came time to build my own CNC table back in 2001 I bought off-the-shelf drives.
The Mini-IO teamed with the 3 or 4 axis bipolar Xylotex 3525/8S series will drive most smaller projects.