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Headless Computer Network Setup RRS feed

  • Question

  • We currently design and manufacture a digital road sign.  The sign contains our own software (written in VB6, transitioning to VB.NET) on a single board computer running XP Embedded.  The sign has a LAN connection and the users can set whether to use DHCP or static addressing / computer name / IP Address & Subnet Mask (static addressing only).  We also have remote software (Windows) that can configure the sign's features as well as its network settings.

    We have been unable to come up with a solution for being able to change the network settings for the signs if a valid connection doesn't already exist.  Since these single board computers are headless with no mouse/keyboard, we need a remote method to change TCP IP settings.  We are using Winsock (VB6) currently using TCP to talk to the signs (same would hold true in .NET).

    I've looked into UDP and broadcasting to all signs on the local network when they would answer back and we could build a list of signs.  We could then use UDP to setup/change each sign's TCP settings for reliable communication.  The problem is that UDP seems only to work if the sign has a valid IP address assigned.  Some of our customers use DHCP w/DNS servers, some just DHCP with no DNS servers and some have no DHCP servers at all and would like us to provide static IP signs.

    I've seen and purchased devices such as serial to Ethernet adapters and printers that can be configured even without a valid IP being assigned, but I forget if a requirement is a DHCP server (thus a valid IP) or not.  Note:  These signs will always be on a local LAN with the computer running the remote software to set it up and "discover" it.

    Can anybody offer some direction?  Thanks!

    Wednesday, April 25, 2012 9:57 PM

Answers

  • Well, I just found my own answer.  UDP protocol does work fine after all (as long as the signs are on a local LAN).  The reason I thought it didn't work in my original posting was that XP Embedded was taking about 50 seconds to get recognized by the network before I could broadcast out to all signs and then get replies.
    • Marked as answer by jhoybs Thursday, April 26, 2012 6:52 PM
    Thursday, April 26, 2012 6:52 PM