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Product tryout: 7-port industrial USB hub
April 23, 2007
Engineers have long questioned the ruggedness of USB connectors because they’re so easy to remove. Sealevel System has solved part of the problem with its SeaI/O-270U, a seven-port hub with unique connectors. Sealevel sent me an evaluation unit. Here’s what I found.
The SeaI/O-270U has tapped holes for the single USB type B (upstream) connector and seven USB type A (downstream) connectors. The hub comes with custom cables that include the screws at both ends, and cables with screws at either the type A or type B end. That’s great for cables connected to the hub. But, it still doesn’t help for the other end where you connect the able to computers or peripherals.
Cables with screws at both ends are good for connecting one SeaI/O-270U hub to another, but not much else. In fact, the mold that holds the screw may get in the way when connected to other USB devices.
The power connection is good for industrial applications because of its screws. At the box, there’s a two-pronged connector, clearly marked “9-30 VDC” with polarity markings. You also get a two-terminal strip that plugs into the power connector. Two screws hold it firmly in place.
The AC adapter comes with exposed, soldered wire ends that you can attach to the terminal strip. One power lead is marked with a “- - -“ marking, which I assumed was positive but I had to check with a DMM. The user manual doesn’t include a description of the AC adapter.
The SeaI/O-270U will relieve some of your concerns with USB connectors, but it should have an LED for each of the seven ports. My $30 home hub has them and this $379 hub should too. The hub, although compatible with USB 2.0 devices, runs at full-speed (12 Mbps), but it does provide 1500 V isolation, something you won't get with a consumer-grade USB hub. The 12 Mbps speed shouldn’t be a problem, because many USB instruments don’t support high-speed USB 2.0 (480 Mbps); they don’t need that speed.
Posted by Martin Rowe on April 23, 2007 | Comments (1)
