Thread: DNC with ethernet/RS232 Terminal servers

Hi,
We are considering getting some software like DNC-Max which will allow us to link up all our machines to a terminal server over an ethernet connection. Can we use any old surplus terminal server for this (eg Shiva SpiderPort) or do we have to buy a special one which apear to be quite pricey. We don't really want to go down the multiport rs232 card route. Is Max-DNC V4 /V5 any good ?

Any advice would be apreciated.

Cheers

Tricky

We write DNC software similar to Cimco's, and our installers use several different types of connections to the machine controllers. The vast majority of CNC controllers out there still use RS232, while the newest ones may have full Ethernet or FTP capability.

To suggest the right PC to run your DNC system, I would need to know a few things about your situation, like:

1) How many CNCs to you have, and what type?
2) Are you "drip-feeding" long files on a regular basis, or do you mostly upload/download to the CNCs memory ?
3) Do you plan to use that PC to run other programs at the same time (CAD/CAM for example)?

I'm sure that Cimco uses the same approach that we use with our PC-DNC Plus system. We load our "PC-DNC Plus Server" software on any PC that's tied to your network. That application software then communicates with the CNC controllers, and it also accesses your NC files through the network. Your actual file library can be anywhere, but we strongly recommend that you keep it on a FILE SERVER of some type, and have a backup system to prevent data loss if a hard drive should fail.

The PC-DNC Plus Server software does all the actual work of communicating with the CNC controls, so it needs enough computer "horsepower" to handle the worst case scenario. Some shops don't ask the DNC system to do much, while others place heavy demands on the system for simultaneous drip-feeding of large files, etc.

While PC-DNC Plus Server is running on one PC, any other PC on your network can run a "PC-CNC Plus Client". The Client just gives you the ability to control the PC-DNC Plus Server from any PC on the network. The Clients can be started and stopped at any time without affecting the DNC system, but the PC-DNC Plus Server PC must be kept running at all times.

The actual DNC connection to your CNC controls can be Direct Ethernet, Ethernet serial hubs, Wireless Ethernet serial ports, USB serial hubs, MultiPort serial cards, or "native" COM ports on your PC. We even use BTR (Behind the Tape Reader) boards to connect very old CNC controls that have no RS232 capability.

By far, most of our installations now use Ethernet Serial Hubs because of their versatility. An Ethernet Serial Hub is a separate box that connects to your network with a single CAT5 network cable. Once connected, it can be "seen" by any PC on your network. We then install device drivers on the PC-DNC Plus Server PC, which maps the serial ports on the hub to that PC. The serial hubs can be located on the shop floor, and short serial cables are run from the hub to each CNC. Hubs are available in 1, 2, 4, or 8-port configurations, and you can use as many hubs as you need to obtain the number of serial ports you need.

USB serial hubs work in a similar way, but the hub must be located close to the PC-DNC Plus Server PC. A USB cable can't be very long. The only advantage to using a USB hub rather than an Ethernet hub is low cost. If you have a lot of serial cables coming to one location near the PC now, and you want to re-use those cables, a USB hub might be a good choice.

Our Wireless Ethernet Adapters can be mounted on each CNC machine, and they communicate with the PC-DNC Plus server via a wireless access point tied to your network. The Wireless adapters are really just a single-port Ethernet Serial Hub combined with a Wireless bridge. Wireless DNC works great in a few situations, but I don't recommend it in others. Be careful when implementing Wireless DNC, you can get burned by people who oversell it.


If you need more info, we'll be glad to help.

Sorry. Just noticed that my long-winded reply didn't answer your question about price.

There are several manufacturers of Ethernet Serial hubs out there. Our favorite is Quatech Corporation, which is here in Hudson Ohio. Their 8-port hubs are a good value. If you shop for the best prices, you can get an 8-port model for about $600.

Just noticed that my long-winded reply didn't answer your question

he is trying to distract you from the truth. cimco does this job better than anyone. dncmax is a great package and can handle your needs. the dncmax network system with ncbase can easily be configured for auto program storage for each machine.

We write DNC software similar to Cimco's

your software is nothing like cimco. who are you trying to fool?

pi: You're an ass. Get a grip.

Besides, you're can't prevent this guy from buying our software. He's in Great Britain, and we don't sell our software in GB. I was trying to offer him some background knowledge to work with. I never said anything negative about Cimco. I can, however, say lots about YOU.

You know nothing about PC-DNC Plus. You can't. You've never even seen it.

Thanks for your input guys,

But what I really wanted to know is:

can I use any old Terminal server eg: a shiva spiderport which has 16 rs232 ports and a choice of ethernet connection types or do do I need a special one which will support odd protcols which may be required when using them with CNC rs232 ports rather than old rs232 dumb terminals which is what most people originally used terminal servers for.

we have a total of 12 machines inc. Mazaks/A2100 Cincinati arrows.

Machine requesting the program rather than sending the program from a pc is essential.

Cheers

tricky

The DNC software shouldn't care what type of Ethernet serial ports you use, so long as it's not a proprietary device. If the serial ports on the Shiva SpiderPort can be mapped as standard COM ports on your PC, then it should work with Cimco, PC-DNC Plus, or any other DNC software.

The special protocols to the CNC controls (Mazatrol CMT protocol, for instance) is handled by the DNC software. The COM ports themselves shouldn't care what the protocol is.

If Cimco is reluctant to endorse the SpiderPort device, it's probably because they're not sure if it's 100% compatible or not. You should be able to get a trial version of the software and use it for a while with the SpiderPort. I know all the DNC companies here in the States will give out 30-day trial versions. The thing to watch out for is a less-than-capable Shiva device driver for the COM port. CNC controls need very "tight" handshaking to prevent buffer overflows, and the Quatech unit has a "Low latency" setting that lets us communicate well even under the most demanding circumstances. I don't know if you'll get the same performance from the SpiderPort. I've read that Shiva was bought out recently, and I'm not sure if you can get info or service on that unit.

How much does Cimco want for new serial hubs in the UK? I managed to find a UK company that handles several device servers, including the Quatech ESE-100D. That's the one we use, and it works well. That site is:

http://www.westbaseuk.com/products.php?cat=31&SID=

Thanks for the digging,

The ones you found are a bit cheaper than what I managed to come up with, but they are still over £500 for a 8 port device.

I guess the thing to do would be to try what I have got first and see what happens.

I used to be a comms engineer and the spiderport was a common bit of kit about 10 years ago, they were very reliable apart from the power supplies, which didn't like getting hot, but we used to overcome this by leaving the lid off !

The spiderport is a complex bit of kit as its remotely manageable, but I think I can turn all this off and make it a bit dumber.

Cheers

Tricky