Messages

5101

General Mach Discussion / Re: Auto Tool-Changer and LPT2

« on: November 22, 2011, 02:26:02 AM »

One thing I did notice on the parallel cable was that on pins 15 and 16, there was also 5.05v, even when there shouldn't be??

That would concern me - it should cleanly switch between Hi and Lo in order to perform the correct logic function.
Perhaps you need to check that your LPT2 is configured and working properly as it sounds that you may have a problem here.

Tweakie.

5102

General Mach Discussion / Re: Probe

« on: November 22, 2011, 02:18:26 AM »

HOWEVER - if the probe contacts are re-made and then re-broken during that decceleration phase, Mach will RE-WRITE that point as the point of contact.

HUM I have never seen it double write the trip point here. Once the initial trip takes place the G31 is no longer actively waiting for a trip it is already into the record and stop sequence of the code. At least that is how Art explained it a long time ago.

Perhaps this point needs to be investigated, at least as it applies to the latest lockdown version - does it re-write or not ??

Tweakie.

5103

General Mach Discussion / Re: Probe

« on: November 21, 2011, 11:55:44 AM »

HOWEVER - if the probe contacts are re-made and then re-broken during that decceleration phase, Mach will RE-WRITE that point as the point of contact.

Thanks Ian - this is something I had never considered (or even thought about happening).

Tweakie.

5104

General Mach Discussion / Re: sharp 10.4 screen

« on: November 21, 2011, 11:34:12 AM »

Hi Tony,

I am sure it can be done but it is really a job for an electronics engineer. The necessary signals are available from the PC graphics chip but the signal levels need to be checked prior to connection to the screen, get it wrong and damage to the screen or PC could occur.
In my opinion, in this instance, the risk is too high for 'trial and error' type electronics.

http://pinouts.ru/Video/VGA15_pinout.shtml

Tweakie.

5105

General Mach Discussion / Re: Probe

« on: November 21, 2011, 11:15:39 AM »

Can this bee sett in the softwhere- "high or low"?

I suppose you could use a 'pull up resistor' for the circuit to be 'active high' and a 'pull down' resistor for the circuit to be 'active low' then configure Mach accordingly.

Another thing I was wondering about,- how accurate is this Probe? Surly there have to bee some play/movement of the ProbeTip before the circut is broken and a signal given. Can this be compensated for by the software?

If it is constructed properly and the spring yields before anything bends then it would be extremely difficult to measure any play/movement in the system. Consider that the tip is essentially resting in the 'V' between 6 points of contact, it will either be making contact or it will not, there is no delay or contact bounce as you may get with, for example, a conventional switch.
When probing there is 'overun' between the contact point and the axis coming to rest but the stored position is the actual point of contact not the final axis position so compensation is automatic really.

Hope this helps.

Tweakie.

5106

General Mach Discussion / Re: Auto Tool-Changer and LPT2

« on: November 21, 2011, 07:01:28 AM »

Yes - between pin 14 and GND (which is pins 18 to 25) should do it.
The cable length will make no difference for this test.

Tweakie.

nb. While you are testing check the cable to make sure you have the right type with Pin 1 connected to Pin 1, Pin 2 to Pin 2, etc

5107

General Mach Discussion / Re: Auto Tool-Changer and LPT2

« on: November 21, 2011, 06:28:27 AM »

Hi Keith,

My mistake, I was thinking in terms of an axis - use whatever control you use to Enable / Disable the pin you are measuring.

Tweakie.

(Thanks for the complements - some of the stuff on the site is quite old now and I keep thinking I must update a lot of it  )

5108

General Mach Discussion / Re: Auto Tool-Changer and LPT2

« on: November 21, 2011, 05:59:11 AM »

Hi Keith,

There is the possibility that your LPT2 parallel card puts out the 3.3 Volt TTL standard and your ATC controller requires the 5 Volt TTL standard.
Perhaps measure the voltage present on the Direction pin - it should be 5 Volts when jog in one direction and 0 Volts when jog in the opposite direction. There are a number of options you can take if only 3.3 Volts is present.

Tweakie.

5109

Mach SDK plugin questions and answers. / Re: Step2Mach - My DIY ethernet controller for Mach

« on: November 21, 2011, 04:17:03 AM »

Excellent work Jarekk.

Tweakie.

5110

General Mach Discussion / Re: Probe

« on: November 21, 2011, 03:36:26 AM »

Johannes,

I don't know if this helps but....

By the method of assembly, all the balls are in electrical contact with the PCB and each of the silver steel pins electrically connects one pair of balls. The, two wire, probe connection is taken from the 'gap' in the PCB track, which under normal circumstances (with balls and pins fitted) is now a short circuit. Any probe contact with an object (no matter from which direction) will open the circuit as at least one pin will fail to bridge the gap between one pair of balls.
It is the software which determines the direction of probing and the probe just indicates when contact is made by breaking an otherwise continuous circuit.

Tweakie.