Jim,
Geckos require 16milliamps to work, the parallel port delivers 10
milliamps per pin. The reason why geckos will work ok with 10
milliamps is because the tolerance of the optoisolators used. So you
just have to be lucky enough to a set of geckos with optoisolators in
the right range. This is the main reason why you should get a
breakout board that buffers the signals.
Arturo Duncan
--- In CAD_CAM_EDM_DRO@..., "Jim Dubois" <jdubois@...>
wrote:
I have a problem with Gecko drives not working, I am assuming I
have
done something stupid or have overlooked something....or will a PC
parallel port not actually "sink" the required 16ma? I have used
the parallel port for control of many drivers, but for what ever
reason the Geckos are not working. This is my first effort with
Gekos....
I have replaced a set of IMS drivers on a formerly functioning
controller with new out of the box Gecko 201 drivers. I have +65
vdc, tied to a chassis ground, I have +5vdc for the common terminal
on the drives, also tied to chassis ground. The parallel port,
also
grounded properly, is communicating with the controller as I can
turn on and turn off the aux devices, ie spindle, coolant and the
like. The power light is "on" on the drives, the motors "lock".
Current setting on the drives is at default, 7 amps. No connection
to the "disable" connection. There are no limit switches or other
complexity...just a 3 axis controller with 2 aux's and the aux's
work.
I have checked out the controller with a different computer, no
change. I have verified the +5vdc to common stays steady. I have
not been able to verify the TTL signals, no scope or logic trace
tools in house. But, it worked with the IMS...so...I would think
it
would work with Gecko.....
any thoughts? do I need a parallel port interface card to drive
the
Gecko's?
