Joint 0 on limit switch

The limit switches work, the motors turn in PNCConf but cannot get anything to work in EMC other than the DRO.

There are 2 of us working on this and this is now our 3rd day of trials with still not much joy. My cheque book or beer money tin is open.
Is there any paid support for LinuxCNC?

type 2 is up/down mode in PNCconf.

It mentions this mode for the 7i48 in PNCconf's help screen when on the Mesa page.

We need more info to help diagnosis your problem.

You say the motors and encoders work in PNCconf but not with AXIS.

So what happens in AXIS?
Does it come out of Estop and the machine will turn on? (I see you have an external estop pin selected)
If it doesn't use halmeter / halconfig to find out why.

This is a servo config, so you should get a following error if you try to move and the motors/encoder doesn't.
Does the encoders work but the motors don't ?

By the way cycle-start, abort and single-step HAL pins are only useful if using TOUCHY interface.

Chris M

Ok some more progress has been made.

Just some background. I have A BSc Elec Eng, several years working with industrial control, 13 years commercial programming and 10 years CNC machining. OK so I'm not some new kid on the block.
The Learning curve for EMC2 is huge. I have been playing with it off and on few a few years now. I even sold 2 x CNC cycle testing machines we built with EMC2 to a major company some time back using Gecko Servo Drives.
I the old version. You just used the software, the configuration program and off it went. We were seriously thinking of going over to MACH3 yesterday. (We being myself and a Mech Eng Student doing his Summer work experience.)

PNCConf is a huge program that creates more headaches than it solves.

Now I have to state my favorite saying "IT IS EASY ONCE ONCE YOU HAVE DONE IT BEFORE"

For a first time initial startup, LinuxCNC would be better off with simple Config utility that just got the basic hardware going. The new potential users would get excited once things turned and then press on to get more working.
It has taken us roughly 30 hours to get the motors to turn. This time was spent in software, Linux, PNCConf and CNC. The hardware was correct from the beginning.

I come back to the statement

"IT IS EASY ONCE ONCE YOU HAVE DONE IT BEFORE"

One issue was 'Joint 0 on following error' . On changing units to mm the default values do not change so RAPID FEED FOLLOWING ERROR goes from 0.005 " to 0.005mm which is not possible. We didn't pick this up.
We also had Limit switch errors, so we eventually disabled the Limit switches.

Next thing is which drive to use for the 5I20. The screen description gives no clue as to which to use. It also defaults to 12 encoders. Why 12 and not 6, which is what 7I48 has? If you know what to look for it's easy.

Ok so now it is running. I have the code:
G00 X0
G00 X10
G00 X0
G00 X10
But the motors only turn through a range of 2.5 to 7.5 (radius) approximately.

Thanks, Wallace.

You say the motors and encoders work in PNCconf but not with AXIS.
So what happens in AXIS?
Does it come out of Estop and the

The fault RAPID FEED FOLLOWING ERROR as the setting was the 0.005 mm.

Thanks for the reply.

marsheng wrote:

Ok some more progress has been made.

PNCConf is a huge program that creates more headaches than it solves.

Now I have to state my favorite saying "IT IS EASY ONCE ONCE YOU HAVE DONE IT BEFORE"

For a first time initial startup, LinuxCNC would be better off with simple Config utility that just got the basic hardware going. The new potential users would get excited once things turned and then press on to get more working.
It has taken us roughly 30 hours to get the motors to turn. This time was spent in software, Linux, PNCConf and CNC. The hardware was correct from the beginning.

I come back to the statement

"IT IS EASY ONCE ONCE YOU HAVE DONE IT BEFORE"

One issue was 'Joint 0 on following error' . On changing units to mm the default values do not change so RAPID FEED FOLLOWING ERROR goes from 0.005 " to 0.005mm which is not possible. We didn't pick this up.
We also had Limit switch errors, so we eventually disabled the Limit switches.

Next thing is which drive to use for the 5I20. The screen description gives no clue as to which to use. It also defaults to 12 encoders. Why 12 and not 6, which is what 7I48 has? If you know what to look for it's easy.

Ok so now it is running. I have the code:
G00 X0
G00 X10
G00 X0
G00 X10
But the motors only turn through a range of 2.5 to 7.5 (radius) approximately.

Thanks, Wallace.

I understand your frustration, linuxcnc is a big pill to swallow all at once.
In fact PNCconf is there to help get basic to medium complex machine running without having to know all the details.
Of course you still need to know some of the details.

Whether it creates more problems then it helps with is hard to qualify - you haven't tried to build a config without it
And comparing a parallel port stepper config built with Stepconf and building a servo config using Mesa, is comparing
apples and apple pie. Both have apples one takes a lot more info and effort to prepare.

That being said,I built and maintain PNCconf so am interested in how to make it better - by now I know Linuxcnc too well so can miss common mistakes.

As for the metric - yes your right PNCconf does not convert the defaults (either does Stepconf) - I could look into that.

Mesa cards are super flexible in the type of I/O it can support then add daughter boards and smart serial daughter boards and there are alot of combinations.
This choice starts with the Main card you buy then goes to firmware.
You complain that PNCconf does not tell you what firmware to use for your board.
How am I (the programmer) supposed to know what you are connecting to the card? The combinations are probably in the thousands.
What info was missing from the manual that would have helped in this regard?

From there now you must choose what components are functional. Again how am I to know what and how many daughter boards you are using?
The encoder counts defaults to 12 because the firmware supports two daughter boards . If you are only using one daughter board you can deselect the extra components and use them for GPIO or leave them active and connect your own hardware directly or ignore them.

I know most of these details don't really matter to a new user - I am just pointing out that the problem is not easily worked around.
But I can look into metric defaults - that should be relatively easy.

Hang in there Linuxcnc really is worth it.

Chris M

marsheng wrote:

Ok some more progress has been made.


Ok so now it is running. I have the code:
G00 X0
G00 X10
G00 X0
G00 X10
But the motors only turn through a range of 2.5 to 7.5 (radius) approximately.

Thanks, Wallace.

Again we are missing some details to help you.
This sounds like it might be a scaling problem. Are your encoders scaled right?
PNCconf's open loop test was a good place to test this but since you have AXIS working you can test there too if you like.
Using halmeter you can look at the encoder count, turn the encoder one revolution and see if the count is very close to what the encoder should be.
When it moves the 7. 5 R, how does it stop? Do you get a following error, does it hunt uncontrollably ?
Have you tuned any PID settings ?

Chris M

Thanks for the open reply. It makes me think some one out there is listening!!

I'll put together a summary on PCONFIG suggestions later.

We have made great progress today, MPG working, servos stepping nicely.


PID
P=1
I=0.05
D=0.01

I increased the axis acceleration to 200 mm/sec/sec and velocity to 6000 mm.min and it now gets to 0 and 10 mm.

Yes please add the suggestions the the PNCcong request page - that would be great!


Ah I'm glad you are winning.
There are lots of smart and helpful people here.
So feel free to ask nice specific questions, with as much background detail you can... We all want you to succeed!