*RESOLVED* CNC11 3.04 Understanding Soft Limits

[bonestock]

I am having some issues sorting soft limits on CNC11 3.04. They do not appear to be behaving as I expect them to.
I have a working system in Mach but have been hitting a few problems trying to get CNC11 up to evaluate.

With the s/w limits set to 0, I can enter MDI and notice that the drives enable. What does not happen is any movement for my MDI commands.
MDI->G01 X2 F5->Cycle Start = Nothing. No errors, no movement, just nothing until I ESC or Estop out of the operation.

With the s/w limits set to "any" non-zero value of 1 to 100, I receive X+/Y+/Z+ Limit Fault messages immediately. The DRO is well within range, heck even the encoder counts are within range but the fault is still triggered.

Am I missing something obvious?

[diycncscott]

I believe you are confusing physical/electrical limits with software travel limits.

Please follow installation GPIO4D/CNC11 installation directions available here
http://www.ajaxcnc.com/tech/downloads/m ... nstall.pdf

That being said:
From the above mentioned manual:

When you press Press F3 -MDI, notice that outputs 17-20 light up. These are the enable
outputs to the servo drives. If the enable outputs do not light up, check that inputs 1-11 and
17-20 are green as displayed above. If they are not, double check your wiring and your
SIPS. If the above inputs are all green and you still don't have enables – double check your
encoder parameter settings. For ANY of the above mentioned inputs, when an input is
open the display state for that input will be red and a fault, limit or estop will be
detected and MOTION DISABLED.

Inputs 17-20 are the Servo Enabled or Drive OK outputs from you drives, if your drives are not setting inputs 17-20, motion will be disabled


1. What is the feedrate override % that is displayed when you use MDI? (0% = no motion)
2. Cycle start = alt-s (not "Enter")
3. Make sure keyboard jogging is enabled (P170 = 1, P148 = 0)
4. alt-j brings up the keyboard jogging screen

Limits/Homes and Software Travel limits:

From the main screen, Physical/electrical limits are set up in F1-Setup -> F3 -Config -> F2-Machine ->F2 -Motor
The numbers in the "Limit" and "Home" Fields represent the PLC input that the limit switch is wired into

From the main screen, Software Travel limits are setup in F1-Setup -> F3 -Config -> F2-Machine ->F1 -Jog
1. The values in "Soft" limits (software travel limits) are the distance and direction an axis can move away from the "home" position of an axis.
2. The "home" position of an axis is always machine zero for that axis.
3. Software travel limits are based on machine position - not "DRO" position or WCS position.
4. Machine zero for any axis is set when (and only when) an M26 command is issued for that axis - such as M26 /x -this is the only way to set (or change) a "machine" position
5. Therefore: If you home to the plus limit of an axis and that axis can travel 30 inches away from that switch, you should input a value of -30.000 in the negative travel limit, and 0 in the positive. If you home to a negative limit for an axis, you should put a positive value in the positive travel limit and a 0 in the negative.
6. You can toggle between display of "machine" position and "part" position on the DRO by pressing alt-d

[bonestock]

I believe you are confusing physical/electrical limits with software travel limits.
...
...
Limits/Homes and Software Travel limits:

From the main screen, Physical/electrical limits are set up in F1-Setup -> F3 -Config -> F2-Machine ->F2 -Motor
The numbers in the "Limit" and "Home" Fields represent the PLC input that the limit switch is wired into

I think that is exactly the problem. I did not realize these numbers were mapping to PLC input.

Thank you for the detailed response. I have been over the documentation so many times I am probably subconsciously missing more and more details.

[bonestock]

Scott, Thanks again. I misunderstood the limit settings on the Motor page to be PLC inputs and not Soft Limit values. Once I set them back to the correct settings the Limit issue ceased to be a problem.

The second problem I had was the feed rate override was indeed set to 0%. Duh. Bumping the feed rate fixed the jogging and MDI motion issues.