Messages

421

General Mach Discussion / Re: losing communication with UC-100

« on: March 21, 2019, 12:41:36 AM »

6" (6 inch) usb cables are included with most (made in China) knock-offs of UC-100.
I think the genuine UC100 came with a 6' (6 foot) USB cable.
Watch
https://www.youtube.com/watch?v=oKU9xN6D06g
He uses a better 15' (15 feet) USB cable for his genuine UC100.

422

General Mach Discussion / Re: losing communication with UC-100

« on: March 20, 2019, 08:27:58 PM »

Another BAND-AID for people using USB motion controllers.
A better quality USB cable MAY help.

423

General Mach Discussion / Re: losing communication with UC-100

« on: March 20, 2019, 07:12:50 PM »

If you read why PLAMACAM use the parallel port to talk to their external motion controller box, you may understand why USB is hopeless.
Read:-
http://plasmacam.com/faqdetail.php?fid=14

The USB cable is like an antennae collecting electromagnetic radiation.
A portable wood router runs at 50/60cycles. That is very low frequency. If you use a VFD spindle you are going up to Higher Frequency. If you run at bigger machine at higher ipm speed, the pulse to drive the motors are becoming much higher frequency.

A shorter USB cable may help. A quality USB cable usually has 2 ferrite sleeves one at each end premolded in. Simple 5 volts signal devices like the USB are unstable because it only needs 1 to 2 volts spikes to affect the signals. Wraping grounded aluminum foil around the whole length of your USB cable can help too.

The Ethernet is better than USB because they use differential amplifiers on both ends of the twisted-pair cable. HF will affect both twisted cables but since the signal is always a difference between the two wires it is NOT affected by EM noise.

The most robust is still the PARALLEL PORT.
That's why PlasmaCAM running on Windows 10 x64 still use the Parallel port to talk to their external motion controller.
Unfortunately MACH3 needs 32bits win7 to use the parallel port.

424

General Mach Discussion / Re: losing communication with UC-100

« on: March 20, 2019, 05:52:59 PM »

now after installing 2010 i'm losing communication with my cnc . i use to take a error every now and then and the machine would stop , but could just hit start again and the job would go on. now i have to reboot the computer to get going again any Ides?

add 1 to 3 ferrite sleaves to your USB cable as temporary measure - see pic.

Permanent solution: Stop using ANY USB external motion controller. They are just not robust or safe enough to control machinery.

Go back to use the parallel port or upgrade to an Ethernet Motion Controller.

425

General Mach Discussion / Re: Mach3 / PMDX-122 Issue

« on: March 20, 2019, 05:28:28 PM »

Hi,

I think PMDX sells a opto-board calls PMDX-105 to "PATCH UP" for the PMDX-122 lack of opto-isolation.

Why bother, this BoB has worked for years in this configuration.

Craig

New version PMDX-122 (REV D) now has a Charge Pump - it is for added SAFETY to prevent machinery motors from moving UNTIL operator using MACH3/4 is FULLY in control.
PMDX-105 optional card is to provide Opto-isolation so that limit/home switches can optionally operate on higher voltages (e.g. 12V or 24V) instead of just TTL level of 5V.
Advantage of higher voltage limit/home switch is that HF noise from VFD & steppers for example will be less likely to falsely trigger the limit switches. HF noise or spikes will have to swing higher voltages to falsely trigger limit switches running at 12V or 24V  instead of 5V.
Another advantage of Opto-isolation is to prevent PC motherboard or parallel ports BLOWING UP. Some companies e.g. Abililty Systems (maker of famous Indexer LPT) used to tell customers to plug in a PCI LPT card or 2 and not use the LPT port on motherboard so that if there is an input surge, you ONLY have to replace the PCI card and not the whole computer.
Opto-isolation prevents blowing up your whole computer or just your PCI/PCIe cards.

People can make their own decision based on more knowledge.

426

General Mach Discussion / Re: Mach3 / PMDX-122 Issue

« on: March 20, 2019, 07:24:31 AM »

I think PMDX sells a opto-board calls PMDX-105 to "PATCH UP" for the PMDX-122 lack of opto-isolation.

Years ago, I saw on ebay a Canadian company selling BOB with extra wires that jumps over the opto-isolation - claiming that the BOB were otherwise faulty.
(They just MISTAKENLY did not connect a 12V supply for the opto-isolation chips).

Some even make videos on youtube WRONGLY "teaching" people how to solder jumper wires.

427

General Mach Discussion / Re: Mach3 / PMDX-122 Issue

« on: March 20, 2019, 04:26:56 AM »

Hi,
reuelt commented:

Input from Limit/home switches etc. can use HIGH voltage and so through opto-isolation chips (sort of relay) for safety reason. The PC USB is grounded with with PC case so USB is NOT isolated from PC.

This is potentially misleading. I have attached the representative digital inputs (DB25 pins 10,11,12,13,15) and none of them are
optically isolated.
Craig

Craig,
if your BOB inputs are not optically isolated, it must be an old model (design).
Most newer models are optically isolated (only for input pins).
See attached PIC.
For this typical BOB board for MACH3, the optical isolation chips (relays) must be powered by 12V to 24V otherwise the input pins will not work.

Gecko G540 spec also says
"Opto-isolation on all LPT signal pins"

Reuel

428

General Mach Discussion / Re: Mach3 / PMDX-122 Issue

« on: March 20, 2019, 12:23:28 AM »

No problem reuelt,
Any input is appreciated.  As far as the USB power...it was working that way when we got it so it was just left that way.  Can you elaborate as to what inputs you would be referring too?  Would the E-Stop be considered an input in said case?

Input from Limit/home switches etc. can use HIGH voltage and so through opto-isolation chips (sort of relay) for safety reason. The PC USB is grounded with with PC case so USB is NOT isolated from PC.
Usually USB power cannot also power the opto-isolation chips (sort of relays). But OUTPUT signal pins from PC will work using USB power. E-stop usually use a large AC relay to switch off a/c so it may still work with USB powering the board.

429

Mach4 General Discussion / Re: Jumpy arcs and curves in Mach4

« on: March 19, 2019, 11:46:30 PM »

You might need to increase the "Lookahead" lines from the default of 200.

430

General Mach Discussion / Re: Mach3 / PMDX-122 Issue

« on: March 19, 2019, 11:10:03 PM »

reuelt,
I tried both Active High and Active Low (restarting Mach after each setting change) and it doesn't make a difference. 

From pic of your PMDX-122, it is the earlier version that does not use a CHARGE PUMP.
The jumper in the middle is already set to ALWAYS ENABLE so you do not need to enable signal from MACH3. Sorry, I only have manual for later version.
Try to supply 5V power though the DC socket and not the USB. Just for testing you can use 4 NI-MH batteries in series that will give 4.8 volts to 5.2 volts.
If USB power is used, the board cannot give INPUT signals to MACH3 because USB power being from the PC cannot (not allowed) to supply power to the OPTO ISOLATOR buffer Chips used for the input signals.