Can ENET RS323 Work on a Workgroup Switch with no Network Uplink?

[jpeabod6]

I have an ENET-RS232 serial device that I hope to use with a PC running Windows 7 64-bit. I understand that NI Serial does not work on my system, so that I must access the serial ports on the ENET through their full VISA resource names, as detailed in this article.

The ENET is part of a mobile cart we are building that houses some measurement/calibration equipment we are trying to automate. The cart also has a cDAQ 9188 ethernet backplane and a workgroup switch on-board. One can hook up a PC to control everything via the workgroup switch. Sometimes the switch is connected to my corporate network, but it is also desirable to operate it with no network uplink. The 9188 works fine with no uplink. I imagine this is what "link local" means?

If I am connected to the network and I configure the ENET device for DHCP, my network assigns it both a hostname and an IP address. I can then communicate with it via a labview VI with no problem. If I remove the connection to the corporate network, the device still works fine until I power it off. Then, upon powering it up again, I cannot use it. It will show up in MAX as "unconfigured". Even if I re-configure it with a fixed IP address, I cannot communicate with it. Since the 9188 can still communicate with the PC over the workgroup switch even with no network uplink, my assumption was that the ENET device would also be able to. Can somebody please clarify for me whether it is possible to do what I want? Please correct my ignorance if not. Thanks very much.

[JRiss]

Does the IP change when powering up the device again?

[jpeabod6]

Thanks for the response; I think I've got it figured out now. To answer your question: Yes, the ENET would preserve its IP in fixed IP mode after I would cycle the power. The reason I couldn't get it to work in fixed IP mode, I discovered, is that I had to re-start Labview after changing it from DHCP to fixed IP mode. I hadn't been doing that before. It must have something to do with the VISA session needing to be killed and re-opened.

I have found that what I can do is to keep the devices on the cart as fixed IP addresses, and then the cart operates as its own little subnet. I can then use the "alternate IP configuration" on my laptop, set to a fixed IP address that the devices on the cart can see. The primary IP configuration on my laptop is still DHCP for my work network, so I can't be connected to the cart and the corporate network at the same time, but as long as I can switch from one to the other without having to keep changing my network settings, it works for me.

Thanks for being willing to help, anyway!.