I can't tell from the last post w/ the connector picture as to what's going on? It appears you should be able to wire in the E-stop and servo ON to the 7i77.
Are you running the machine w/ the Crusader RED card powered on?
Also, my guess is that the e-stop wiring is 'logic' only and not e-stop shut-off for the drives. I can't tell from the schematic how that's powered, but it seems like it should be able to be connected to the 7i77. You need to find out what's on the other end of the e-stop wires, ie where's power and ground? GUESSING, maybe the RED Crusader card supplies ground and power and then you can simply move those to a 24vdc power supply on one end and the mesa 7i77 on the other??
Need to confirm via the schematics or tracing the wiring in the control box.
Sorry I've been away awhile working either with or on my backhoe. Anyway, Yes the "Red Card" is controlling both the E-stop, reset of the servos, and the limit switches. Linuxcnc is powering the amp cards and reading the scales.
I looked at some DC-DC transformers . I assume thats what would be required to power the E-stop and limits but I am real fuzzy on where the power would be connected to the 7i77 board. Also developing a hal file to operate the E-stop, limit switches, and reset button are all new to me. I did some reading and there was an example of a hal set up for a test E-stop / reset that look like it could be adapted.
Another knot in my head is caused by readings of 36 volts at the limit switches. With matching 36 volt called out in the schematic. Would 24 volts operate the system with no problems??
No eBay APP ID and/or Cert ID defined in Kunena configurationCould this ebay dc-dc boost converter be used to provide 24v power for the E-stop / limit circuit?
Power to this would come from a ATA power supply that is now being used to power the 7i77 card.
Meanwell makes lower-end cost effective power supplies and I would rate them a tad higher than ebay items. The one I linked to above is 120Vac input and 24Vdc output, but that would work for you fine, I think.
One question I don't know the answer to is how much isolation is there for the meanwell or the ebay item. I would guess they're both not great...
jamby wrote: I assume thats what would be required to power the E-stop and limits but I am real fuzzy on where the power would be connected to the 7i77 board. Also developing a hal file to operate the E-stop, limit switches, and reset button are all new to me. I did some reading and there was an example of a hal set up for a test E-stop / reset that look like it could be adapted.
FROM THE MESA 7I77 MANUAL: Inputs are sinking type. That is they sense positive input voltages relative to field ground. Output are sourcing type, that is they supply field power to field ground referred loads.
See the attached schematic that I hand drew. On the top, I show you a latching E-stop circuit that you might consider to use. The reason is that estops controlled by a computer is not an ideal way to do it. W/ the latching circuit, the Estop, reset, and contactor work to turn on/off the power to your servos. Also, I pulled off 24VDC and wired that to the 7i77 to show you how to hook that up so that linuxcnc could then 'shut down' on an estop condition. I don't
FROM my HAL file as an example...
# ---estop signals---
net estop-out <= iocontrol.0.user-enable-out
net estop-out => iocontrol.0.emc-enable-in
# --- MACHINE-IS-ENABLED ---
net machine-is-enabled hm2_5i25.0.7i77.0.0.output-00
net machine-is-enabled <= motion.motion-enabled
You would have some HAL connections something like this and would have to try it...
net estop_connection hm2_5i25.0.7i77.0.0.output-00 => iocontrol.0.emc-enable-in
jamby wrote: Another knot in my head is caused by readings of 36 volts at the limit switches. With matching 36 volt called out in the schematic. Would 24 volts operate the system with no problems?
36Vdc is odd to me. I would guess 24vdc would work, but depends on the rating/type of switch. If they're 'contacts' that open/close upon actuation of the switch, then 24vdc will work fine. See attached file.
On the bottom half of the attachment I show how you connect in Inputs to the 7i77 and one output from the 7i77. The output 'sources' 24vdc which means you need to take it to GND or your 0VDC on the 24Vdc power supply. For the inputs, you source 24 vdc through you device and the 7i77 takes it to 0vdc.
Mark
Sorry but I don't have a good understanding of the idea of "isolation". I had thought it had to do with a common ground, as in all circuits having the same ground?
