Problem with ethernet connection - Technology Forum - Home Theater, Computer, Televisions, Personal Electronics and more!

hotshot · 08-10-2006, 02:41 AM

Hello,

I encountered a problem with DECrepeater 90T-16.

I have an ethernet-enabled embedded control product that has worked properly for almost two years. Recently I got a phone call from our customer that says this product has difficult to work with DECrepeater 90T-16.

The customer sent back this product along with the DECrepeater 90T-16.
I checked this product and no problem found. Actually this product works fine with many hubs in our company such as D-link DE-809TC and etc. Also I didn't find any problem with DECrepeater 90T-16. I connected several PCs to this hub and they can communicate with each other properly.

But if I connect this product to DECrepeater 90T-16 then this product cannot establish an ethernet connection. The Port State LED in DECrepeater 90T-16 for the port which this product is connected to is always off. But other devices/PCs that are connected to this hub work fine. When I ping this product from a PC no reply at all. And I checked the IP statistics from this product console menu and found there were no ethernet RX interrupts.

Here I would like to mention that this embedded product uses RTL8019AS ethernet controller and its built-in 10BasedT transceiver.

I am wondering any of you experienced this before. Could this problem be caused by physical signal level mismatch?

Thanks for your help.

heartbomb · 08-10-2006, 02:42 AM

What is the product? Do you need a crossover cabel instead of a patch cable?

hotshot · 08-10-2006, 02:42 AM

Make sure your using Cat5 patch cable or a Cat5 Crossover cable whichever you need.

heartbomb · 08-10-2006, 02:42 AM

Thank you all for reply.

This product is an embedded real-time monitoring and alarming device.

I double-checked the UTP port pin-outs of that product and it needs a Cat5 patch cable to connect to the hub. I did use a Cat5 patch cable when connecting this product to DECrepeater. When I use this cable to connect this product to D-link DE-809TC hub it works fine.

Thanks,

hotshot · 08-10-2006, 02:43 AM

Is there any reason you need to be using a repeater instead of a hub here?

heartbomb · 08-10-2006, 02:43 AM

Are you connecting to an uplink port or is the uplink port not activated?

hotshot · 08-10-2006, 02:43 AM

Hi,

For this embedded network-enabled product it doesn't need to use a repeater for establishing the ethernet connectivity. Actually this product works properly with many hubs. Just recently one of our customers uses DECrepeater 90T-16 to connect our product into their LAN and found this issue. DECpeater 90T-16 is a 16-port repeater, so it is just a hub.

Now there is a D-LINK DE-809TC hub sitting on my desk and when I connect this embedded product to this hub it communicates well with all other devices that are connected to this hub.

BTW, DECpeater 90T-16 dose not have uplink port.

Thanks,

heartbomb · 08-10-2006, 02:44 AM

It appearrs your best bet is contacting the tech support for the device you are hving trouble with and seek their advice...

hotshot · 08-10-2006, 02:44 AM

I tried to do that.
Unfortunately DEC (Digital Equipment Corporation) was acquired by Compaq, which was then acquired by Hewlett-Packard.
The DEDrepeater 90T-16 is a bit old and it seems difficult to find technical support for this device.

Anyway, thanks you all for your help.

heartbomb · 08-10-2006, 02:44 AM

Well, if it works fine with a hub, and you can't get tech support for it, why not just replace the repeater with a hub? Then at least it will be working, and you don't need to kill yourself finding whatever minor issue causes the problem. Especially as you have no resources to communicate with anyone else who might be using the same combination of products, and found a solution.