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You may get a bit more speed by increasing the inm's scan rate from its default
20 KHz to say 100 KHz (this decreases the default digital filter fast time constant (5 clocks)
from 250 usec to 50 usec)

1. If you use the 7I96S firmware with MPGs on P1 it would just be the second inm (inm 1)

2. No, you need to use differential receivers (say 26LS32)  for that

3. its a bit tricky because LinuxCNC has many offsets in its DRO readouts
at the minimum you would need to set this offset. 
(perhaps by using the scale components  offset pin or manually resetting
the counters at 0)

Many CNC controls do not require a new line (or block) of g-code to repeat a G0, G1, G2, or G3 code on a new line if they are not changing from the previous lines, because those codes are considered "modal" (ie they are remembered). This allowed controls to save precious memory space, from the days of paper tape and when 1024k was considered a significant amount of memory. Linuxcnc is no different and will work fine with the extra repeated g-codes omitted.

Your problem with arc radii not matching the begining and end is an unrelated problem, and results from your cam program taking liberties with rounding errors. Usually there are settings in the cam program to adjust how closely the cam program must calculate the arc radius. What those settings are called and were to find them are not always straight forward or easy to figure out. (I'm not familiar with your cam program to make suggestions there.)

There are settings in Linuxcnc that will allow you to change the limits where an alarm will be set for these radius calculations. See this part of the Linuxcnc documentation.
linuxcnc.org/docs/2.9/html/config/ini-co...sub:ini:sec:rs274ngc

Works very well, no problems.
Thanks

Ok, zelo, do a quick test to see if the speed doubles if you reduce the scale by half


Murphy, were you one of the guys modding the board for better encoder signals?
500rpm @ 2400cpr isnt very fast, does it continue counting if you lower speed?
You will probably need to halscope it. I dont know how many people are using encoders with the rt1052

Your PID and deadband settings. I suggest bringing the topic into the Remora ethernet thread

edit, oh man this was an old thread

Wow, off the rails is definately where that went.....fascist? Where on earth did that come from? We're talking about serial protocols....I don't think I tried to suppress your freedom from my keyboard.

Point was you theres some kind of misunderstanding about how asyncronous serial works, even though that post was edited out of existance now. I have no idea what this last post has to do with anything. All I said was in service to Baudrate != Bitrate. Though it's generally OK to colloquially just say it like it does.

Moved to EtherCAT section.

2.7.n is probably Debian Wheezy, so it can not be upgraded to 2.9.3 due to changes in Python, mostly.
For Wheezy, you need to use
sudo apt-get update
sudo apt-get upgrade
It might just upgrade to 2.8.n as that was the last Python 2 version of LinuxCNC, although Wheezy has reached it's "end of life" a long time ago so no more updates for it.
-
You can install the new 2.9.3 from the downloads page, and if it tells you it can not find files/usb device, just unplug the USB, wait 5 seconds, plug in the USB, wait 10 seconds, click on continue/next.
Be aware that if using an old PC, it is much better to use the Ubintu version i linked above or the existing Wheezy version as they use RTAI kernel, while the new ones use RT-Preempt kernels and thy will have worse latency on old systems.

Hi Rod,

Thank you for the leg up on the development environment. I've spent a chunk of time with it.

Should I use this forum thread to have conversations or would somewhere else be better?

Tom

Nice and thank you!
Applied the fix -self. to tool_actor.py and confirmed now fixed for me.

Now to add my spindle encoder, looking forward to testing the conversational part

PCW wrote:

The MPG encoders are part of the inm module, so in halshow,
select hm2_7i96s.0.inm.00.enc0-count

Note that these are just raw counts and would need
the scale component to scale to position.

It might be easier to have some normal encoders brought out on the
parallel expansion connector since standard encoders have scaling built in.

 

I did a little test using hm2_7i96s.0.inm.00.enc0-count driving a HAL scale and it works very well as long as I move the carriage at moderate speeds.If I turn the hand wheel as fast as possible I loose counts as expected.

So next up try the pins on the P1 expansion port (ESD carefully).

Three questions if you don't mind:
1) How would I use or map the expansion port pins to be used as 'A', 'B'  quadrature encoder inputs and where would I find them in HAL?
2) One of my scales has differential outputs 'A' ,'A-',  &  'B', 'B-'. all within the range of 0-5V so when 'A' is +5V, 'A-' is 0V etc. Can four expansion port pins be used to accommodate differential quadrature signalling or just single ended?

I order a fair number of PCB's and I get free PCB vouchers, so I will probably make a little daughter board either with fast opto's, or perhaps just a series resistor and TVS's (need to think about that) to be on the FPGA safe side. However I would like to do a proof of concept first.

3) Assuming I have created a HAL net with the DRO value and now I want to display that in Axis as a DRO value, what target parameter do i need to send the DRO value to?    And, assuming my commanded values will differ from the scale values because of backlash, which displayed value in axis represents the commanded value, and which one represents the actual (scale read value)?

Much appreciated.



 

Any idea why they PV and raw count stop counting after a certain RPM. When I am in hal show I can see it counting up. But if I increase the rpm(it's not much rpm maybe 500rpm) it stops counting up. 
Its a 600ppr, supposed to be 100khz encoder.  Encoder scaled to 2400 in the hal file.

1: After a lot of playing around, I think I found the flaws in my thinking.  First of all, the variables in the INI file MUST be capital.  So changing my file as below allowed me to use it as a READ ONLY variable.

[TOOLSETTER]
Z_TOOL = -1
Z_TOOL_HOME = -0.1
X_TOOL_HOME = 0
Y_TOOL_HOME = -10.25

2: You cannot CAN NOT use the ini variables as a regular read / write variable.  Is this brought out in the documentation?  I must have glossed over it .. see this:  Nowhere in here does it state capital or read only state.  I think that needs to be added to the manual.

3: So that begs another question...  is there any script that can be configured to run on initialization of LinuxCNC so we can create variables and set them to certain values? I don't remember reading anything like that in the manual.   It would be nice if the ini section had an entry for that.I can't really mark this solved, because of the remarks I made here. Yes, I have a better understanding now.. IF I am correct in my assumptions.  But it has led to some confusion, and days wasted troubleshooting this.  ( I have been programming since 1967, long retired now. )

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thanks for reply to me,
I am using 2.7.15 version of linuxcnc , I want to update from 2.7.15 to 2.9.3,but Debian terminal does not take code like sudo apt install .... or sudo apt update /upgradeI.Debian send to message me thar Terminal is locked to code
gooddays

Ok, so I have flashed the card with 7i96s_2pwmd which changes STEP4 to a PWM output. Then connect the STEP4- output on the mesa card with TTL on the laser controller and the same with GND on both sides.
HAL config as per this discussion:
forum.linuxcnc.org/27-driver-boards/5480...and-wiring-for-laser

 

 

That correct? Thanks.