bob@alsys1.aecom.yu.edu (Bob Lummis) (09/10/90)
I am planning the installation of an 802.3 backbone in several campus buildings. It will included extensive unshielded twisted pair runs, and 110-type wiring blocks. I have to go through a formal bidding process and have the entire campus wired in one job. I am now trying to figure out how to write a bid document, and subsequently a contract, that will guarantee a good cable plant. I could require a series of tests on the cable after it is installed that will demonstrate that each of the requirements in the 10BASE-T draft standard are individually met, but that isn't very practical unless there is a document that describes such a series of tests in practical terms that a contractor can be expected to use in the field (i.e., type of test instrument, how to hook up, what to read, etc.). Or maybe I could specify certain 10BASE-T equipment that should be attached to the cable plant and successfully used (whatever that means) for a certain period of time. That seems too hard, and at the same time not stringent enough. Or maybe I should specify all of the component types myself and spell out in fine detail exactly how they should be installed. This is not good enough for our business people because it means I am relying on statements from equipment manufacturers as to the performance of their equipment, even tho they cannot be held accountable for the success of our particular installation. Bear in mind that what I need to produce is a written document that will guarantee (legalistically) a correct cable plant the first time (i.e., without any extra cost additions or changes following installation). Any advice from those who have done it? Any sample bid documents I could look at? bob@aecom.yu.edu (Bob Lummis)
brianr@hprnd.rose.hp.com (Brian Ripley) (09/29/90)
Hewlett-Packard makes an instrument that was designed to do just what you want. The HP28687A Wire Test Instrument tests for continuity, attenuation, and crosstalk of installed twisted pair wire. The instrument will tell you if any parameters are outside of the specifications.