Need Help!- Help with DNC please

[Chris C]

Hi

Newbie to the site and needing some pretty urgent advice

Basically, I work from a large firm within the toolroom. We use Vero VISI machining software and to date has been fine.

However recently we have been experiencing problems with the DNC cable, it seems to be spiking and blowing the comms ports on the pc. We have replaced several ports to get it working again and have since started using usb - rs232 converters, but we have also managed to blow them too!! they work fine for a period of time and then we get the "buffer overflow" error message.

1 of our electricians is going to make a new cable up but we need the cable layout diagram?? I'm presuming we can just replicate the old cable as somewhere along the lines it might be damaged?

The control is Fanuc F15M and we are using a 9pin to 25 pin cable.

I do have the option of using a 25 pin to 25 pin cable but do not have a diagram for the cable for it.

Also, i have been looking into wireless DNC. Is it worth it? And are there any recomendations.

The DNC we use is "DNC Manager" that came with the Vero VISI software and we drip feed the programs in so the cable needs to support handshaking??

Please excuse any errors i may have mentioned as this is all relatively new to me

Any help is greatly appreciated

Regards

Chris

[MicroMill]

Hey Chris,
Did you resolve this, or still need help? Wireless generally is bad news in a shop floor environment.

[angelw]

Originally Posted by Chris C Hi Newbie to the site and needing some pretty urgent advice Basically, I work from a large firm within the toolroom. We use Vero VISI machining software and to date has been fine. However recently we have been experiencing problems with the DNC cable, it seems to be spiking and blowing the comms ports on the pc. We have replaced several ports to get it working again and have since started using usb - rs232 converters, but we have also managed to blow them too!! they work fine for a period of time and then we get the "buffer overflow" error message. 1 of our electricians is going to make a new cable up but we need the cable layout diagram?? I'm presuming we can just replicate the old cable as somewhere along the lines it might be damaged? The control is Fanuc F15M and we are using a 9pin to 25 pin cable. I do have the option of using a 25 pin to 25 pin cable but do not have a diagram for the cable for it. Also, i have been looking into wireless DNC. Is it worth it? And are there any recomendations. The DNC we use is "DNC Manager" that came with the Vero VISI software and we drip feed the programs in so the cable needs to support handshaking?? Please excuse any errors i may have mentioned as this is all relatively new to me Any help is greatly appreciated Regards Chris

Chris,
What cable pin out are you using? Some will suggest that the cable shield be connected to ground at both ends of the cable. Grounding the Shield at both ends (both devices) can lead to Ground Loops. A Ground Loop can occur when any two devices are grounded in Different Places, or if one device is not grounded well enough. For example, you may experience a ground loop when you connect a PC and a CNC control together with a serial data cable, if the CNC machine has a ground stake driven through the shop floor, and your Personal Computer is grounded via the AC wall socket, or if one device is not grounded well enough. The ground loop occurs when there is a different electrical potential between the Grounds of the two devices. This results in an electrical current being conducted through the data cable. and can burn out the IC chips that send and receive the RS232 serial signals, if the difference in potential is greater than about 30 volts. Accordingly, unless good grounding to the same ground can be assured for both devices, its recommended to ground the shield at the CNC end only.

You won't gain anything by using a DB25 to DB25 cable configuration over a DB9 connecter at the PC end, but to ensure that you have the cable configured correctly, the following is correct for Software Handshaking (Xon Xoff).

Xon Xoff Handshaking cable configuration
Machine Side ---------------------------------- PC Side
DB25 Male Connecter ---------------- DB25 Female -------- DB9 Female
1 Cable Shield ------------------------ Not Connected ----- Not Connected
2 --------------------------------------------- 3 --------------------- 2
3 --------------------------------------------- 2 --------------------- 3
4
| Bridged
5

6
|
8 All Bridged
|
20

7 --------------------------------------------- 7 -------------------- 5


If the above cable configuration is used, make sure that parameter #5001 = 3 and #5110 = 3.

Regards,

Bill

[Chris C]

Hi

Thanks for the reply

We have now sorted it, I replaced the cable with a like for like. The connections on the original were a little ropey to say the least. So made a new one and so far (6 weeks) it has ran faultlessly.

Chris