[Mike1000]

Hi guys,

I have bought a Pendant of type Mach III P4S from Vistacnc
I run it on a PC with Windows XP SP3, Mach 3 version R3.043.066 DEMO mode (evaluating at the moment)
The PC has a Pentium 2,8 GHz CPU and 2GB of RAM.
Running parallel port and Gecko 540 drive.

I have a couple of problems:

1) There is a significant time lag from when I am turning the pendant wheel to when the CNC table starts to move. (As the USB bus is a very fast bus, no more than a few milliseconds latency should be caused by the USB transmission).

Can you please help me identify what may be causing that problem?
See link to video showing the problem here
https://www.youtube.com/watch?v=iYd4G_CHyAM

2) When approaching the soft limits from either side there is no slowdown of the movement . The table "bangs" into the soft limit without speed reduction. (same problem on all axes). Is this normal (I hope not)? This happens when I am using the pendant but when I move the table with the PC keyboard or the +/- keys on the pendant it slows down OK.

Here it "bangs" into the end stop
https://www.youtube.com/watch?v=POpvmnCZ43Q (run with pendant)

Here it slows down OK
https://www.youtube.com/watch?v=JPSGomGBBVI (run with buttons, not with wheel on pendant)

3) The movement continues for significant time after I stop turning the button https://www.youtube.com/watch?v=POpvmnCZ43Q
Seems like there is a "buffer of events" stored that has to be emptied before it stops.
However a pendant should be a real time device. Big latency cannot be tolerated (and it can be dangerous causing tool and mechanical crashes as well)


4) There has been several software crashes. Mach 3 has crashed and I had to forcibly terminate and reboot the PC. This happened after installing the Vista pendant. Everything looked ok before installing the Vista pendant. Any known solution to this?

Any hints to what is going on? Too slow PC? Can it be the case that the pendant normally actually is slow and sluggish like that?(hope not!) Settings problem?

I am also considering LinuxCNC by the way.

Next question:
I need an ethernet stepper controller for the G540 that is well supported, fairly recent design, can run both LinuxCNC and Mach3 and is reasonably priced. Any hints on a good product matching this spec? (4 axis)

[Torchhead]

Hi guys,

I have bought a Pendant of type Mach III P4S from Vistacnc
I run it on a PC with Windows XP SP3, Mach 3 version R3.043.066 DEMO mode (evaluating at the moment)
The PC has a Pentium 2,8 GHz CPU and 2GB of RAM.
Running parallel port and Gecko 540 drive.

I have a couple of problems:

1) There is a significant time lag from when I am turning the pendant wheel to when the CNC table starts to move. (As the USB bus is a very fast bus, no more than a few milliseconds latency should be caused by the USB transmission).

Can you please help me identify what may be causing that problem?
See link to video showing the problem here

Its not the USB its the plugin running in MACh and having to interface to the internal functiosn OR (worse) using somthing like MODBux to read the encoder. Jogging is done with lower acceleration and at slower rates set by the JOG Speed . It all depends on how they implemented the interface
Plug-ins run in a slow ring (.1 sec per loop) and a faster .02 sec per loop) Reading encoders in real time has never been a long suite of MACH3.

2) When approaching the soft limits from either side there is no slowdown of the movement . The table "bangs" into the soft limit without speed reduction. (same problem on all axes). Is this normal (I hope not)? This happens when I am using the pendant but when I move the table with the PC keyboard or the +/- keys on the pendant it slows down OK.

Same basic answer. It depends on how they call the homing sequence. Soft limits don't work too well unless you zero at the homes FIRST.

3) The movement continues for significant time after I stop turning the button
Seems like there is a "buffer of events" stored that has to be emptied before it stops.
However a pendant should be a real time device. Big latency cannot be tolerated (and it can be dangerous causing tool and mechanical crashes as well)

Sorry but it all depends on how the interface to the USB is writtten. USB is not a great protocal for feedback either . Its a polling protocaol so the master (PC USB port) has to asjk a device if it has traffic then setup a "session"...after that is pretty fast as long as the stream is not interrupted

4) There has been several software crashes. Mach 3 has crashed and I had to forcibly terminate and reboot the PC. This happened after installing the Vista pendant. Everything looked ok before installing the Vista pendant. Any known solution to this?

Yes unload the Pendant drivers and quit using it (sorry) A faster PC MIGHT help because plugins take up more overhead.

Any hints to what is going on? Too slow PC? Can it be the case that the pendant normally actually is slow and sluggish like that?(hope not!) Settings problem?

That would be a question for the vendor of the pendant

I am also considering LinuxCNC by the way.

Next question:
I need an ethernet stepper controller for the G540 that is well supported, fairly recent design, can run both LinuxCNC and Mach3 and is reasonably priced. Any hints on a good product matching this spec? (4 axis)

Most Ethernet cards will not run with BOTH MACH and LINUXCNC. Either / Or . Totally different interface and drivers .
Ethernet Smooth Stepper (Warp 9) has MACH3 plug ins and probably the most popular for MACH3. Made in the USA and uses well written plugins for MACH3 and MACH4

Most of the I/O willl be wasted if you plug to a G540 and use its internal single port BoB
Mesa has several cards for LINUXCNC but support will have to be from the LINUXCNC groups

TOMcaudle
Home

[ger21]

First thing I would try is to install Mach3 version 3.043.062. Version .066 is known to be very buggy.
Then I would contact VistaCNC and ask them about their product.

As Tom said, there are NO motion controllers that will work with both Mach3 and LinuxCNC.