Re: Turning Spindle Off and On

--- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers <rogersmach@y...>
wrote:

>
> Other breakout boards have the ability to control Solid state

relays however like the PMDX has no "watchdog" feature that monitors
erroneous pulses from the PC (it didnt two years ago anyway and they
didnt sound too concerned about changing it)

Your posting is unclear. From the http://www.pmdx.com web site:

PMDX-121
Buffered Breakout Board with "charge pump"
Lower cost alternative to the PMDX-120 opto-isolated breakout board
Priced at $77 each - click here for details and purchase options.

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The PMDX-121 is a motion control breakout board for interfacing with
the parallel port of an IBM-PC style computer

+Supports all signals present on a standard printer port. (8 data, 5
input, 4 output)

+Buffers signals to protect the PC's printer port.

+Utilizes standard printer cable for connection to PC.

+Provides LED status indicators on the 5 input and 4 output signals.

+Supports the MACH2 "charge pump" signal to inhibit outputs when the
MACH2 software is not running.

+Inhibits outputs when E-Stop or Fault inputs are asserted.

+Reports E-Stop to computer on loss of power, E-Stop loop open, or
Fault input grounded.

+Provides one 10 Amp. relay on board for spindle or other I/O output
function.

+Inputs have pull-ups to +5 volts and are filtered to suppress noise.

+Step and direction outputs from data bits can be common ground or
common +5 volts for driving opto inputs.

+All I/O connections are made via wire clamp screw terminal strips.

+Auxiliary +5 volt DC output available to power sensors.

+Three power supply options. (external DC, external AC, or USB port
power steal)

+LED to indicate "outputs enabled" status so "charge pump" status
can be seen.

+Jumpers to control "charge pump" functionality.

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Are you saying that there is something besides the charge pump that
should be included in the PMDX board, that is in fact included in
the Campbell board?

Fred Smith - IMService
THE source for lowcost Cad-Cam and desktop CNC
http://www.cadcamcadcam.com/hobby