Communications

[Toolio Iglacius]

Hi all,

I use mastercams built in communications funtion to dnc link my HAAS verticals with High speed machining.

Recently I have a had a few mishaps, ie gouges that weren't present in verifying, and the mysterious thing is I can run the programs through again and they do not gouge

Is it possible the dnc link is failing to send over the program error free every time? The pc sending is fast.

Any thoughts appreciated.

[s0l0seven]

do you have error checking/parity on.

[cadcam]

Toolio,

1) What are you using for cable?

2) How far is the machine from the computer?

3) Does your cable hang with any electrical lines or pipes?

4) What is the speed that you are DNCing at?

(Example 4800 baud or higher)

Some of these things can be cause for loosing data or data dropping.

[Toolio Iglacius]

My cable is just plain old 4 core data cable.

And I have now realized it does run along side some electrical cabling. The machine is only a few meters away but the cabling runs up the wall and along a rafter, approx 20-25 mtrs (60 feet).

(hmm doesnt sound good now I think about it)

My baud rate is 38400, I thought this was necesary for HSM. I have parity set to even.

Perhaps cabling with better insulation/shielding will help?

[ 01-20-2002: Message edited by: Toolio Iglacius ]

[Claus@Cimco]

Hi

It looks like you are missing somekind of handshake between your Cnc-machine and PC. please check that the machine are running with hardware or software handshake and your pc does the same.

The mastercam dnc doesn't support hardware handshake but the cimco dnc and editor in mastercam does.

Claus@cimco

[cadcam]

It does sound like a cabling issue to me.

Shielded cable that long is much better.

And if you do have to run along electrical you want the cable to be shielded.

I say this because you are dropping characters once in a while not every time, correct?

60 feet is becoming a dissent length in most cases if you are close like the desk is right next to the CNC you can get away with cheap cabling.

JM2C

[Toolio Iglacius]

Yes it drops characters every once in a while only, some of my programs might have 1 million plus lines, but I only have this problem occasionaly.

Thanks for the tips.

[John_Carpenter]

Hi,

 

The HAAS controller has an issue with XON/XOFF synchronization in regards to handshaking...set the parameter to USE DC1-DC4 codes instead. Also - HAAS controllers have a RS422 connector right below the RS232 connector. RS422 is far superior to RS232 for signal transmission. Buy yourself an RS232 to RS422 converter from B&B Electronics (or a similiar supplier) and connect to the machine that way.

One of the engineers that works with me also reported that on an earlier version of the HAAS controller he could only get it to DNC properly by using RTS/CTS synchronization. Keep in mind that this would require those lines to be connected (pins 4 & 5 on the machine) and as stated in an earlier reply that hardware handshaking would have to be available on the computer software.

As far as cable length goes - the rule of thumb is for good quality RS232 cable (shielded and less than 30 pico-Farads/foot capacitance) you can reliably send 19200 baud using 50 ft cable; For every half of baud rate you can double the length of cable. And vice versa going the other way -- At 38400 baud you should only be using 25ft of RS232 cable. 60ft is pushing it; Lower your baud rate and check the performance.

 

Hope this helps