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Author Topic: Do not allow any movement until servo drives ready  (Read 5947 times)

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Offline Hood

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Re: Do not allow any movement until servo drives ready
« Reply #10 on: November 13, 2011, 05:40:58 PM »
Will mach ver4 have convencional ladder ?

Filipe
Dont think so, I have been wanting ladder logic for a while but Brian doesnt seem to like it. He has what he says is a better way that is much more powerful but so far I dont know much about it :(
I am hoping its as easy as conventional ladder logic and not just easy for programmers ;D
Hood
Re: Do not allow any movement until servo drives ready
« Reply #11 on: November 13, 2011, 05:57:13 PM »
You should be able to use the same logic without all the complex brain then. I did not have the option of knowing my drives were not ready. Create a brain that watches the LED and uses the toggle axis on commands. The problem if I remember is that the toggle commands do just that, toggle to the opposite state it currently is in. So the logic would need to know what the current state is. There was not a function to turn it off or on directly. My guess would be to use your enable line and your user led to define the current state and toggle if required. So if enabled and in fault toggle axis (assumes it was on). It's been a while sense I was in the brain editor so I'm just giving ideas here.

Offline BR549

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Re: Do not allow any movement until servo drives ready
« Reply #12 on: November 13, 2011, 06:11:46 PM »
WHy not chain all the drives as to the drive good signal and feed it into the estop in Mach3. Until the drives all go good Mach3 cannot come out of Estop so it cannot be made to move.

Just a thought, (;-) TP
Re: Do not allow any movement until servo drives ready
« Reply #13 on: November 13, 2011, 06:15:17 PM »
WHy not chain all the drives as to the drive good signal and feed it into the estop in Mach3. Until the drives all go good Mach3 cannot come out of Estop so it cannot be made to move.

Just a thought, (;-) TP

I my setup at least you can't enable the drives while in estop. So you could never get out of estop.

Offline Hood

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Re: Do not allow any movement until servo drives ready
« Reply #14 on: November 13, 2011, 06:18:39 PM »
Thats more or less what I do Terry, problem is he is relying on Mach to enable the drives before he can get the signal and I presume is using the chargepump off in reset mode so drives would never get enabled and thus no ready signal. I power my drives from my E-Stop chain and watch for a fault output from my drives rather than a ready signal.
Hood
Re: Do not allow any movement until servo drives ready
« Reply #15 on: November 13, 2011, 07:22:11 PM »
One thought on this issue. Is your drive ready signal really a fault condition or a separate signal line? I assume it is based on your explanation but wanted to be sure as they need to be handled in completely different ways. A drive fault should estop the machine. Mach3 is open loop so no matter how quick you respond to a drive fault your actual position and Mach3 DRO's will be off if the axis was in motion during the fault. Just wanted to make sure we are on the same page.

An actual drive ready signal line not used as a fault line then can be handled with a brain. Basically you toggle the axis' off when you send the enable signal to the drive and toggle back on after the drive ready input comes. This will also toggle again on a state change on the drive ready line from that point.

That all said there is merit to Hood's method of hardware enabling your drives. I actually do both just in different ways. My hardware estop cuts the AC to the DC power supply running the drives. Mach3's software estop (Reset) disables the drives using the enable line on the drives. I also tie back in the drive faults to mach3's software estop as well as the hardware estop. Basically you can't Reset Mach3 while in hardware estop. That's just how I chose to do it. My thought was if I hit the estop button I don't want any power going to the drives just in case the drive has failed.

Offline BR549

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Re: Do not allow any movement until servo drives ready
« Reply #16 on: November 13, 2011, 08:34:41 PM »
I do it as Hood does the system estop is a seperate circuit that kills power to all drives and signals Mach3.  I would never allow Mach3 to software control the actual estop function.

(;-)TP
Re: Do not allow any movement until servo drives ready
« Reply #17 on: November 13, 2011, 10:31:47 PM »
Do you enable the drives from Mach3?
Re: Do not allow any movement until servo drives ready
« Reply #18 on: November 14, 2011, 01:46:41 AM »
I enable the drives with the charge pump, this is drives will be ready after the reset is unchecked, and mach is ready. If I reset mach because of the servos status mach will not ever stay off reset. This would be a safew procedure if Mach was able to do what I want - only axis movement if a condition is set.
The toggle axis can be a thing thing try. Thank you on that.