Panelview plus to SLC 5/05 Ethernet

[LMDAVE29 0]

I have a SLC 5/05 Processor and a Paneview 600+ 24 VDC screen. When I connect to Panelview to an ethetnet cat5 hub and the processor to the hub, everything is fine, but When I connect the cat5 directly from the panelview to the SLC, I have no communications. Is the hub neccessary. I've seen another system with it direct connected, the only differece is the panelview was 120 VAC. BUt, I have no communication when direct connected, but if I plug both in the hub, things start talking. Any help is appreciated.

[Eddie Willers 2]

The difference is that when you connect to a hub or switch, you are using a "Patch Cable". When you connect one host to another, you must use a "Crossover Cable".

[paulengr 44]

First off, throw away that hub. It will ALWAYS cut your maximum speeds in half by it's very nature. They frequently have other problems that you can't quite explain but eliminating them always gets rid of the problem. The cost difference between a hub and a switch is so small that it's not worth using them these days. Hubs used to be faster latency-wise with 10 Mbps but since most switches are now wire speed (they begin retransmitting the packet even before the packet is fully received) and now operating at 100 Mbps, this very slight latency advantage has completely disappeared. Just wire up everything using CAT 5E and use 10/100 Mbps switches. You will never be sorry. CAT 6 is a waste of money because it's somewhat of an orphan cable (similar to CAT 4) other than the fact that the cabling is more round and easier to pull if you can get comparable pricing compared to CAT 5E. Bandwidth is moderately better than CAT 5E but 1 Gbps copper Ethernet is designed to work on CAT 5E, and 10 Gbps Ethernet could never be squeezed enough to fit onto a CAT 6 cable (CAT 7 is already in development/standardization). Second, in the "old days", you would run an MDI (media device interface) cable between devices and the closest switch or hub. Any patch cable that you buy is almost automatically an MDI cable. Between hubs/switches, you would use an MDI-X (media device interface-crossover) cable. This way the logic (which pins are transmit and which are receive) is identical on all ports. These days, most switches, even the super-cheap ones, automatically do "auto MDI/MDI-X negotiation"...you don't have to worry about this detail anymore. Hence the reason that any time I need an MDI-X cable, I have to google a wiring diagram. If you want to wire up directly between devices, you need an MDI-X cable. I only have a single one in the entire plant and I keep it buried very deep in a drawer so that nobody will accidentally use it thinking that it's a "normal" cable.