Re: [CAD_CAM_EDM_DRO] connection of ground pins

In a message dated 01-Feb-02 00:09:36 Central Standard Time, motionin@...
writes:

> Pins 18-25 are all grounds, right? Should I solder them together?
>

Rick: First question: Yes, well, S'POSEDta be! Second question: Some
might say "Nah, not necessary", but I have seen some of those PRC
printer-cables with only pin-18 actually wired "through", and the other seven
left open! So, it can't "hurt" just to spiral a bit of freshly-stripped #28
"WW wire" around each, and neatly solder 'em. Then, you might "get away"
with only one conductor in the cable from one connector to the other, as
"ground", since all-8 pins would be "shorted together". If using an
inexpensive "printer-cable", you might use an audible continuity-checker
(hey, that's a buzzer and a battery! 21st C. high-tech!) and "see" what pins
"go through" before you goof summin up. Yes, each of those 8 is "ideally"
supposed to be one of a twisted pair for each of the 8 "data lines", pins 2
thru 9. I have found, too, that the alum.-foil shield and any "drain wire"
is often not even connected to the metal shells on the connector-ends! You
might consider this, if you are soldering-on a DB-25 "from scratch".

The use of opto-isolator inputs to whatever stepper-logic, etc., you want to
control with the PC's PPort will do WONDERS to stop all that "surprise
stepping" when some AC turns on, across the room, or someone comes in and
turns the overhead lights off, until you HOLLER, and then snaps 'em back, ON,
again! The Gecko drives (and Superior Electric's DP-2000 series) have those
opto-inputs, and, while they "want a few mA more input-current", it is WORTH
the trubble! A 74HCXX gate can easily "fire" these opto-inputs.

As Ball End OH always ends, "Hope this helps!" Jan Rowland, old troll


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