Gnds, and more Gnds and Gecko's Questions..........

I am finally making progress on my control panel again, for the EMCO Compact
5 CNC Lathe I am converting....
Tim, will be here tonight and want to persuade him to help me set it
up..............

In the mean time I have questions about grounds,

I am using an early Wonderboard that has two separate 5 volts supplies. One
is marked (Comp). The other is (Ext). The two +5 volts supplies are
completely isolated from each other

The first one is a +5 volts (Comp), supply with its ground connected only to
the computer ground, and the ground for the Opto Isolators on the input side.

Its +5 volts is providing, thru 1 K pull-up resistors, the power for the
input side of the Opto Isolators only, from the computer.
It is not a +5 that comes from the computer itself, it is a separate power
supply, on the Wonderboard.

The second +5 volt (EXT). Supply, is for the external Opto Isolator circuit
to the drives, it is feeding the output side of the Opto isolators, I will be
using these signals for the step and direction to the drives.

Questions:
1. When using the Opto Isolated circuit, do I still connect the computer
ground to the main power supply ground???????? This would tie the controller
to the electrically isolated Computer/Parallel port if I do......It is
isolated now, with its own Opto Isolated circuits and the separate +5 volt
(Comp). Power supply, on the Wonderboard.

2. Am I correct, that, the +5 (EXT). volt supply that feeds the output side
of the Opto Isolators, is the same + 5 volts that goes to the Gecko's?????
This output side is where I am getting the step and dir signals for the Gecko
320's.

3. Do I do anything with the Ground of that +5 volt (EXT). supply?? This is
the Ground that is for the output side of the Opto Isolators that are feeding
the step, dir, and +5 volts to the Gecko's.
I have it connected to the controller main power supply ground now, is this
correct??? Or should it be floating??? Or connected some where to the
Gecko's?????? This is the - of the +5 going to the Gecko's, assuming I am
correct in question #2.

Gecko 320 questions:
EStop
5. I am using relays to select the power on and off to the Gecko's, for
driver selection. The cabinet has X, Y, Z, and A drives. For the lathe I
will only be using X and Z, later the same cabinet will be controlling a
Mill, and using X, Y, Z, and sometimes A.

The relays drop out under an EStop or Fault, I have 470 MFD caps mounted
right at the Gecko's G-320 terminals.

6. When dropping the relays with an EStop or Fault, will this cause any
problems for the Gecko 320's?? Can I drop/isolate both the Power Supply +
and - with the relays or will dropping both cause a problem for the
Gecko's??? This would happen in an E stop or Fault situation only, or if the
drives were not selected for operation.

7. I have some 1000 MFD capacitors, that I could mount at the output side of
the relays, would this be good for the G-320's in an EStop Stop condition or
Fault to allow them to have more capacitance during shutdown????? Assuming
breaking both the + and the - at the same time.

bill
The longest member of the group without anything running.............