Messages

2131

General Mach Discussion / Re: Mach3 and latest ESS Driver - threading now works!

« on: August 10, 2019, 06:56:26 PM »

Hi TP,
UCCNC                      UCCNC is not a feedback controller, neither are any of the UC**** boards ergo not PID capable
PathPilot Mesa card    No idea what PathPilot is.....is it realtime PID capable?
PathPilot LPT              See above
LinuxCNC Mesa Card   LinuxCNC is realtime capable and can be programmed to do realtime PID....if Linux is your thing
LinuxCNC LPT             See above
CommandCNC            No idea what CommandCNC is.....is it realtime PID capable?
CSlabs                       Yes CSMIO/A is realtime PID capable at 600Euro, shame about the buggy/lacking Mach4 plugin
PoKeys                       PoKeys has an on board API that allows for proportional control but cannot do PID
Centroid Acorn           A rather more expensive albeit complete solution....not Mach
Centroid Analog         See above

Two that should be on this list are:
Hicon                       With the activation to do PID $1200, good Mach4 plugin
Gallil                        Starts at $2000 for three axis, recently released Mach4 plugin.

In short there are only three boards that allow genuine PID with Mach, CSMIO/A, Hicon and Galill....all of then way
more expensive than an ESS.
LinuxCNC is capable if Linux is your thing...and that debate is as old as hobby CNC itself.

Craig

2132

Mach4 Toolbox / Re: Versions of the Mach4 Mill manual

« on: August 10, 2019, 05:02:08 PM »

Hi,
I have build 4162 installed and it came complete with this manual including a few pages (only) of chapter 6.

Craig

2133

General Mach Discussion / Re: Mach3 and latest ESS Driver - threading now works!

« on: August 10, 2019, 10:25:35 AM »

Hi TP,

Simple because other modern DIY controllers CAN do rigid tapping

Name them and then price them.

Craig

2134

General Mach Discussion / Re: Mach3 and latest ESS Driver - threading now works!

« on: August 09, 2019, 11:56:56 PM »

Hi Roger,

I believe the FPGA in the ESS can handle pulse frequencies to over 100 kHz, and possible much higher. I think this is fast enough for a spindle.

I suspect that the internal frequencies of the FPGA are very much faster than that. The limitation is the means of measuring speed,
the delay between the speed being established and the time that speed is reported to the ESS. I think the ESS solution
would be inadequate for a position mode servo of several hundred Hz bandwidth but does a fine job for a velocity mode
spindle.

I think this is the good news....the ESS now has the capability to make threading a doable proposition for machines
that don't have hugely overpowered spindles. Warp9 should be congratulated for their effort.

I am less certain that progressing the ESS to a high bandwidth position mode controller is either viable or desirable. The cost of
those controllers that are capable of that performance are beyond my budget and I would be lost if Warp9 persued that
avenue. Additionally the ever increasing capability of servo/drives render the need for  motion controllers to do such a thing
moot.

Craig

2135

General Mach Discussion / Re: Mach3 and latest ESS Driver - threading now works!

« on: August 09, 2019, 08:30:53 PM »

Hi TP,
I think having both A,B and index channels for rigid tapping is effectively requiring the ESS to be a position mode
feedback controller.

Warp9 have steadfastly refused to dip their toes into that market.......just the support required alone would be a nightmare.

This solution offers a reasonably tight (approx. 50Hz bandwidth with Mach4 and probably 10-15Hz with Mach3) velocity mode
feedback control. This is without having to offer genuine servo type performance, ie bandwidths of hundreds of Hz.

With the superb and increasingly cheap AC servos on the market and Mach4 being able to run out-of-band axes and/or a
coordinated C axis, and able to swap to either mode under program control, what would be the advantage to Warp9 to
compete against that sort thing?

My understanding is that both the Hicon and the CSMIO/A both have the feedback control to enact servo type performance,
but even the cheapest is four-five times the price of an ESS. Of course Galill is the undisputed master of this sort of motion
control but at eye-watering prices.

My contention is that Warp9 have avoided the trap of offering such advanced features that would see the price inflate out of
the hobbyist market....particularly in view of the trend for AC servos and drives to become ever smarter and do all the required
extra 'fruity bits' without the ESS having to raise a sweat.

Craig

2136

Mach4 General Discussion / Re: Add More Software Input Signals

« on: August 09, 2019, 07:59:20 PM »

Hi,
just thinking about my previous post:

Thus if you had a number of inputs each attached to a register

How would you do that? If you have an input on the Hicon you have to signal it to Mach using a signal.....ie one of the signals
in Machs predefined list.....therafter you could update an iregs register. But having to use one of Machs signals rather defeats the
purpose.

I'm now thinking that using iregs is not a solution to your problem. Its not because iregs aren't useful...they certainly are but you
have to use a Mach signal to connect your input pin to an iregs register.

The Hicon obviously has a whole bunch of registers which it creates, at least one for every pin and without having to use one
of Machs signals. Is there any reason that you don't want to use the Hicon generated registers?.

The same caveat applies as before....you need to poll the registers for input events of interest.

Craig

2137

Mach4 General Discussion / Re: Add More Software Input Signals

« on: August 09, 2019, 07:47:30 PM »

Hi,

If I follow your answer to a previous post regarding custom iregs I can achieve the same thing without the HiCON plugin.

That is my understanding. You can create registers without restriction. They are accessible throughout Mach, irrespective of
which chunk, module, panel or whatever.

They are not a signal however. As you know whenever a Mach defined signal changes state the signal script runs. Thus you
don't have to monitor or poll the signals.....the signal script will run when any of them change and you can determine if
it is the signal you are interested in by having an entry in the signal library table (SigLib{}).

A register could change however and you would not know it unless you stopped what you were doing and read the register.
Thus if you had a number of inputs each attached to a register you would need to poll them on a regular basis to know if any of them
has changed. That could be a substantial program burden depending on the frequency which you determine you need to get
updates and on how efficient your code is.

Craig

2138

General Mach Discussion / Re: Mach3 and latest ESS Driver - threading now works!

« on: August 09, 2019, 06:04:47 PM »

Hi Roger,

My understanding is that this feature is available for both Mach3 and Mach4 now. However, for me it removes most any reasons for switching from Mach3 to Mach4, as Mach3 now does everything I want.

Mach3 enacts proportional only feedback whereas Mach4 offers genuine PID.

While PID control sounds good, and it is a marked improvement over what was, it is still a long way short of servo control.

Firstly there is the means that the ESS derives its speed updates...by timing between pulses. Thus you have a resolution/
refresh rate compromise to make. A regular servo gets its speed information not differentiating its input pulse stream,
aka timing between pulses, but by monitoring the feedback term of a high gain integrator loop. This achieves the same
result, namely providing an estimate of the differentiated input stream but with an order of magnitude better noise
performance, especially at low speeds.

Secondly because Mach uses only one channel of the encoder it has no sense of direction. The PID feedback loop controls
velocity only and has to wait for a speed update for the duration of the interval between pulses associated with the speed
measuring procedure. Therefore the resolution/refresh rate compromise is doubly fraught because is the same compromise
that determines the delay between a speed change and the estimate of that speed change being available to the feedback
controller.

Any delay between physical event and an estimate of that event to a control system counts VERY heavily against
its stability and bandwidth.

For this reason the spindle PID offered by the ESS is good, certainly much better than we've ever had before it still
pales into insignificance to the bandwidth and accuracy of a servo loop....and before you say but this is a spindle.....
remember Mach4 has out-of-band axes that can be driven independently of the coordinated axes but with exactly the
same tight control of a coordinated axis.

Craig

2139

Mach4 General Discussion / Re: Creating M-Code to activate Outputs

« on: August 09, 2019, 05:05:53 PM »

Hi,
I notice the file is machipc.dll not machip.dll........just the sort of typo that can catch you out.

Craig

2140

Mach4 General Discussion / Re: Creating M-Code to activate Outputs

« on: August 09, 2019, 05:01:19 PM »

Hi,
that's the same build as I'm using.

Have a look in Mach4Hobby/Modules for the file machip.dll  Is it there?

Craig