contact us Easy to use DNC software for RS232 CNC machines - free 60 day trial


Q. Will it run on the new Windows 10?

A. Yes it runs just fine in Windows 10.. For more info on Windows 10 installation click here...

Q. Will it run on Vista or Windows 7 & 8?

A. Yes we have customers using Win 7 & 8 (32bit & 64bit) no problem at all. dnc4U will run on Windows 95, 98, 2000, ME, NT4, XP, Vista & Win 7 & 8 & Win10. We do not really recommend Win95 though. For more info on Vista installation click here, Windows 7 installation click here... and Windows 8 here....

Q. After I install dnc4U for the first time, it will not load when I click the icon.

A. Right mouse click the dnc4U icon, and "Run As Administrator". That should make the software run everytime.

Q. After I install dnc4U for the first time, it says there are zero days left.

A. Right mouse click the dnc4U icon, and "Run As Administrator". That should make the software run for 60 days. If it still will not load, download the version of dnc4U that performs an online license check.

Q. I get error message "component MSCOMCTL.OCX or one of its dependencies not correctly registered; file missing or invalid."

A. Right mouse click the dnc4U icon, and "Run As Administrator". Unless you already have administrator rights, then on newer systems that have secure permissions some controls are unable to register during usage.

Q. After I purchase what else will I get?

A. dnc4U is only available via electronic-download, so you won't receive any boxes, CD's or printed manuals. You will receive a link to your licence keyfile by e-mail immediately after purchase, you should check your spam folder if it does not arrive as it is always without exception emailed to you, it will be your system that blocks it. In addition you will also receive an invoice (VAT number if entered too) by email very shortly afterwards.

Q. I've purchased dnc4U but I haven't received anything yet.

A. All purchase and product fulfillment are through FastSpring a trusted reseller for As soon as you make the purchase, you will receive several e-mails for your order. One of these will contain links to your licence keyfile, so please look in your spam folder if nothing arrives. Also please do make sure that you enter your own e-mail address correctly or we may find it impossible to contact you until you contact us asking where it is!.

If you have an email address from an ISP like AOL or maybe a free-account, then we have recently noticed their e-mail filters are actually blocking e-mails coming through, and customers assume that we have not sent anything, but we always do!. We now send the information as a URL within the e-mail rather than an attachment, as anti-virus and firewalls may block those with attachments. Just click the hyperlink and save the unlock keyfile to your desktop- then follow the easy to use instructions in the e-mail.

Q. I need to change computer will the software code still work?

A. No it won't, however we are happy to replace the code FOR FREE.

For replacement keys please email us!

Give the NEW software code, if possible the OLD software code

And the COMPANY NAME that it was bought under, we will email a replacement back ASAP

Q. Why two versions of dnc4U?.

A. We have two versions because it has become increasingly difficult to store the trial period in the registry. As security on computers has increased, and computers have become more locked down by default, it is more difficult to keep track of the trial period. As a result, many installs simply fail after a few days. This is more prevalent with Vista, Win7, Win 8 and Win 10. In addition, after purchase the license is often blocked by microsoft security features. We have therefore developed a second version that performs the license check on our server. ALL WE STORE IS THE SOFTWARE CODE, START DATE AND DAYS RUN. After purchase, the license is automatically generated and downloaded to dnc4U via our server, all in the background, making registration much easier. So, if the first version without a permanent connection fails, try the second version.

Q. Why isn't my USB to Serial adapter working?

A. Since the release of Windows XP many laptop manufacturers no longer have a "proper" serial port at the back. Notable exceptions are quite recent IBM Thinkpads and some Dells with the docking station. Instead there are only USB ports. As a result users are finding that a USB to serial adapter is the only way they have to communicate with their CNC machines.

Unfortunately all USB convertors are not created equal, especially if they contain the "prolific" chipset. Devices intended for use at home are now expected to work in the harsh industrial environment, and unfortunately many are not up to the job. Many manufacturers of USB to serial adapters are not 100% compatible and communication to with CNC machines is either unreliable, very slow, or limited to one way transfer.

For laptops you could use a PCMCIA/Express to serial card, they are far superior and often not much more expensive, preferably with some form of isolation.

If you must use a USB device, then we have used Keyspan USB to RS232 adaptor cables - they work great when others just don't >> Click Here or Here and are reasonably priced. We have reports from several users that MOXA are also reliable.

Please take time to watch this video for additional information and resources about USB devices from BB-Electronics. This company sells more robust rugged USB devices (albeit more expensive) much more suited to industrial applications Often it is worth spending more money initially, than wasting time when you cannot get the USB to work.

Unfortunately it's not as simple as listing USB to RS232 devices that work for one user, because sometimes the same one will not work for another. So whilst we list several options above, there is just no 100% guarantee that any will work with your computer.

Quite often we think that it is well worth the while to buy a secondhand laptop off ebay with a proper serial port. In many cases this would work out cheaper and far more reliable than having to buy things such as USBs or Express cards.

Q. When I try to change the CNC settings, it says I have insufficient access to save the changes away.

A. This is because you do not have rights to edit the settings file. This file is called "dnc4u-settings.ini" and is located in the dnc4U folder.

Right click the "dnc4u-settings.ini" file, and then click properties
Click the security tab
Under group or user names, click your name and see the permissions you have. You need full control

Q. Will dnc4U work with my CNC?

A. This is one of the most commonly asked questions. All we can say is that if your CNC supports the RS232 protocol, then yes it will. We even supply a list of predefined CNC templates to get you started for many popular machines. We do not support exotic proprietory protocols that are outside the scope of RS232, such as LSV2, Fidia etc.

Q. What computer access rights should I give?

A. dnc4U needs to be able to create temporary files and be able to write to your system registry. If it can't it may lock you out saying its expired. If you get this, then you should do the standard thing of giving users full access and then gradually tighten things up. For typical use, a standard "power user" would be just perfect, they have Modify, Read/Execute, Read and Write properties.

You should install dnc4U using Admin rights and run the software at least once with admin rights to ensure correct operation and installation of dnc4U.

Q. Do I need any specific hardware to use dnc4U?

A. Depends. If you are using a PC computer or a laptop that has a free com-port in the back then no you dont need anything extra. If you are using a newer laptop, then the odds are that you may have a USB port only, in which case the cheapest a USB to Serial cable convertor, they are cheap only about $30 However, we always recommend either PCMCIA or EXpress cards as they are usually far more reliable than USB

Q. Can I send and receive to more than one CNC machine at a time?

A. Yes you can run up to 64 CNC machines at once, simultaneously, all you need do is load dnc4U as many times as you need it, because you can run up to 64 "instances" of dnc4U at the same time. You do however, need a free communication port for each CNC transmission. You can get multi-port serial cards, we really like MOXA we've used them for years and they are really easy to setup.

Q. How much is all this going to cost me ?

A. You can see our latest price list click here.. We give great discounts for multiple purchases, and once you have bought there are no upgrade costs, ever.

Q. Does dnc4U support Heidenhain Blockwise for drip feeding large files?

A. Yes.

Q. Does dnc4U support Haas Xmodem for drip-feeding large files?

A. Yes.

Q. Does dnc4U support Mazatrol?

A. No.

Q. Does dnc4U support transfers using Fanuc Data Server?

A. Yes. You can use the optional ftp pack to transfer files as a client to the Fanuc data server.

Q. Does dnc4U support direct TCP/IP transfers to Wireless devices?

A. Yes. You can use the optional wireless pack to transfer direct to wireless or ethernet devices using an IP and port, so bypassing the need for virtual com ports. In this mode simultaneous transfers to multiple machines is possible.

Q. I receive files from my CNC and after a while the data is garbage then OK then garbage again.

A. You need to either turn off your communication port receive FIFO buffer or reduce the receive value to its smallest level. You access these by going into Windows Control Panel, Device Manager, LPT & Com Ports. Select your com port and click the advanced tab. Then turn off the FIFO option. You may need to do this for each of your com ports. Also tweak the size of the receive buffer inside dnc4U, this can affect older computers.

Q. I try and send or receive a file and all I see are XXXXXX.

A. dnc4U has expired. To purchase we need your computer software code. You get this by clicking the register menu and entering this info onto our webpage.

Q. After I receive the unlock file it does not register.

A. Please follow the instructions in our e-mail that we send you after purchase. You have to do it in a specific sequence. We have never had a code fail, we are afraid it is always down to incorrect input or failure to follow our instructions.

Additional Info for Vista, Win7 & Win 8 & Win10

Q. Do you charge an annual maintenance fee?

A. No we hate that idea, unlike other DNC software vendors we don't do it, once you have paid for dnc4U that's it. You can download the latest version at all times free of charge. We do not notify you either as we don't want to send you any spam, its entirely up to you if and when you want to upgrade. FREE LIFTIME UPGRADES

Q. I want to run dnc4U on more than one computer, can I copy dnc4U onto more than one computer with a single license?

A. You need a license for every computer you run dnc4U on. We look at it this way. If you made 100 parts for one of your customers, would you charge him for 1 part or for 100 parts ? However, we have price breaks and we offer very good discounts for multiple licenses.

Q. Which languages does dnc4U support?

A. dnc4U is only available in English BUT - you can fully customize the texts, menus and buttons into your own language

Q. I'm drip feeding large files and it stops after a few hours with a timeout message?

A. dnc4U sends data in bursts, usually block by block, but also in constant sized chunks. Either way it will stop if an XOFF is sent (or the CTS goes low) and will not start again until an XON is received (or CTS goes high). If your CNC is taking a long time to interpret the NC code then dnc4U will timeout after 600 seconds - it assumes that transfer has stopped because nothing has happened for this length of time. If this happens to you, increase the timeout to say 36000. This means dnc4U will not timeout for 10 hours, enough time to restart drip-feeding - there is no increase in cycle time whatever value you use (we also recommend that you turn off the receive FIFO buffer and turn off all power saving features such as screen savers etc)

Q. Its says its expired, I have never run dnc4U before?

A. If you have NEVER run the software before, then you do not have sufficient access rights and permissions to run the software. You should log in as administrator - this will see if that cures the problem. Then get your IT guy to slacken up on some of the access rights. The installation setup has a file called diagnose.exe, run this and run the test. You need read/write access to the registry - use regedit and set permissions for users to access the registry. For XP, Vista and Win7 we always recommend that you run the software "as administrator" simply by right mouse clicking the dnc4U icon and selecting that option from the list.

If this still happens, try our online license check version of dnc4U with a permanent internet connection.

Q. I'm drip feeding large files do I need to do anything special?

A. Not all CNC will drip-feed, so you should consult your manual to see if it uses special protocols. But basically drip-feeding on CNC's like Fanuc, Haas and many Japanese and US CNC's is simply a case of handshaking between your PC and CNC. We would always recommend that you turn off or reduce to minimum value the receive FIFO buffer. If you use a com port that shares an IRQ with another device such as a mouse or modem, that this other com port is not used. ie com1 shares an IRQ with com3 and com2 shares an IRQ with com4. All screen saving devices and power management devices are turned off. Some USB devices can "go to sleep" after a while and if data is sent every 20 minutes, which is common, then the USB may not respond either fast enough or not at all to any XON/XOFF etc.

Q. What is dnc4U export information?

A. ECCN=5D992



Privacy & Cookie Policy   Website Terms & Conditions
Try Out One Of Our Other Products - Check Out Our Product Comparison Matrix
Website and all user downloadable DNC software ©2017 DNC Software Ltd
All Trademarks acknowledged E & OE
DNC Software Ltd
Registered in England : No. 7384997
Registered Office : 3 Meynell St, Wildsworth, Gainsborough, Lincs, DN21 3DX, United Kingdom