PDMX 126 with AM822 drivers and relays.

[dachopper]

again#2

[JAZZCNC]

Don't like this setup because you don't have latching safety circuit. How you have it now soon as you release the E-stop the system becomes active again regardless if the fault is cleared or not.

Personally, I would run the E-Stop thru Master relay wired so forms latch. This then controls the Killing of power to high powered devices like Drives, Vfd etc. Then informs PMDX E-stop occurred which then does the Rest and turns off its Outputs. The Master Relay can only be Reset by pressing Momentary Button and will only allow the Relay to reset if all faults are clear.
The E-stop circuit can then be run using 24V giving better noise immunity.

[dachopper]

Ok, But latching or not, the software that is running the machine will go into reset condition the second it receives an E-stop or limit switch touched, until someone physically pushes the reset button in the software, and then clicks on start again in the software. So regardless of weather the E-stop remains latched or not, The PDMX will not activate anything again as the software is in reset active mode? A latching circuit is adding another layer of buttons I have to press to get the machine started again.

What do you think about the load I was placing on the K2 relay? All i did was look at the rated Watts, or Amps per motor and figure out what that would be at 240 Volts ( 100% conversion) to guess the load at max drain for everything on? It says 10A max in the manual

[m_c]

A key rule is never to trust software!

What size of machine is this?
Personally, I'd ensure the e-stop circuit removed all power to anything that moves directly, which if I remember correctly from the PMDX manual, the BOB will kill all outputs as soon as the E-stop signal is lost. However, I'd add an extra relay (the onboard relay is probably not ideally rated for handling PSU start-up surges) controlled directly by the E-stop circuit (adding a reset/latch is reasonably easy - they are a legal requirement for commercial use, but hobbyist use you can do whatever you want as long as it's only you that's going to risk getting injured), which controls power to the drives.
If the E-stop directly controls the main power relay, then you can use an extra set of contacts in the relay to switch the BOB E-stop input. Unless you're using more than about one KW/KVA of power supply, I'd use a common DIN rail mounted DPDT 10A relay. RS part numbers are 488-2610 for the relay, and 803-376 for the socket to give you an idea of the type - other sources are available.

Having the main drive power supply active without the BOB active is not a problem, as the BOB/software should prevent any motion from occurring. The big problem arises when you rely on the software to kill things, and the reason you want to kill things is because the software isn't doing what it should, so you really want to make sure the E-stop kills everything, even if the computer/software is doing it's very best to not stop things.

[JAZZCNC]

Ok, But latching or not, the software that is running the machine will go into reset condition the second it receives an E-stop or limit switch touched, until someone physically pushes the reset button in the software, and then clicks on start again in the software. So regardless of weather the E-stop remains latched or not, The PDMX will not activate anything again as the software is in reset active mode? A latching circuit is adding another layer of buttons I have to press to get the machine started again.

What do you think about the load I was placing on the K2 relay? All i did was look at the rated Watts, or Amps per motor and figure out what that would be at 240 Volts ( 100% conversion) to guess the load at max drain for everything on? It says 10A max in the manual

Was going to answer this then noticed Moray did the job for me.
Everyone does it there own way just some do it better than others, it's down to you to decide if think yours is better or not.!

[dachopper]

JAZZ, most of my faults have been detected by controllers etc, but regarding the 882 error loop..... Do you know, or does anyone know 100% that it is the main motor DC power that needs to be cycled in order to clear the fault?

How are guys doing this? just Cutting the Active line before the ac/dc converter using a low voltage DC press button through a relay?

Redone Schematic, can't decide where to put the E-stop. In the pic, it overrides everything, and turns the pdmx off, but keeps the motion controller on as I don't want to cut that off.

Option 2, is rely on the pdmx safety E-stop circuit, as it will cut power to spindle / motion commands / dust extractor and coolant. then I can on / off the motors if needed to clear fault separately?

I'm normally no where near this machine when it's running, as the jobs are hours long, and I rely on it turning itself off when it faults, not sitting there watching it non stop - as such the e-stop rarely gets used as I'm not there ( No-one is )

[Neale]

How are guys doing this? just Cutting the Active line before the ac/dc converter using a low voltage DC press button through a relay?

My machine uses dual motors/ballscrews on X axis, driven by EM806 (very similar to 882), so I'm a bit paranoid about stopping everything if one of the motors stalls to avoid tearing the gantry apart. To do this, I've wired the fault outputs of drivers in series with e-stop switches (all three of them) so hitting e-stop or fault signal from any driver do the same thing. I also use a safety relay with latching function. Relay is energised by momentary action switch and will drop out on e-stop or fault. Safety relay contacts (a) cut power to second relay which removes a.c. power from driver power supply, (b) cut enable signal to drivers, (c) send signal to motion controller e-stop input (I'm using CSMIO IP/M). So on fault, driver loses power so resetting safety relay (front panel push button) will reapply power and reset driver. So far, all driver faults have been motor stall, when I was trying to drive X a bit too fast. Dropped max rapid speed for X and it's been fine since.

It all depends on your paranoia quotient, but with a largely unattended machine I would probably do something similar - safety relay does the basic "stop everything" actions while the motion controller does other bits and pieces in the background, but I don't rely on it for primary safety. Downside, maybe, is that you have to hit front panel button as well as reset button in Mach3 to restart but that's not a big deal.

One man's view - I'm sure others will do it differently.

[JAZZCNC]

JAZZ, most of my faults have been detected by controllers etc, but regarding the 882 error loop..... Do you know, or does anyone know 100% that it is the main motor DC power that needs to be cycled in order to clear the fault?

You have two choices to clear the Fault. Recycle power to the drives or use the Enable input.
To use the Enable input for a reset you'll need to set it up in the software. Then setup a Drive Reset button which cycles the Enable input.

Like has been suggested most use latching circuit because it's safest approach and kill power so the drives get reset by default so not an issue.

Take your pick.!

[dachopper]

Using the enable input tickles my fancy. So I could run a series wire to a single pin, and send an enable active high/low signal to the drives. Then if the software goes into reset, the enable signal should stop all drives at the same time. Then if I click software reset, that will re-enable all drives up again as it turns enable back on.