© 2010 Ugur Akinci
Network manual writing is an important niche within technical communication. Given the fact that there are countless networks all around the world consisting of computers, printers, scanners, readers, detectors, cameras, security and peripheral devices, the need for documenting them is constant and universal.
And here is the catch: a “good” network writer needs to know a lot of technical terms and concepts. Ideally, she should be an engineer who can write well. But short of that, a writer can also train himself by learning the basic terms of the trade.
Here are two basic terms that every network document writer should know and understand very well: RS-485, and RS-232.
These are both “network protocol” terms, denoting both the way in which data is transferred around a network and the physical venue through which such transmission takes place.
RS-232 is called a “point-to-point” protocol since it connects two components to one another and nothing else. RS-485 is a “multi-point” protocol since it can connect multiple network components to one another.
RS-232 is used to transfer network signals across short distances, up to 30-60 meters, or 50 ft. It allows only 1 Driver and 1 Receiver; for example, a Computer hooked up to a card reader. 232 uses non-twisted wire for transmission.
RS-485, in contrast, is used to send signals over long distances, up to 1,200 meters, or 4,000 feet. You can link 32 Drivers to 32 Receivers “down stream.” RS-485 uses twisted-pair wire to cancel magnetic interference.
More technical details:
RS-232 operates in full-duplex mode: the components on both ends of a 232 link can send and receive signals at the same time. RS-485, on the other hand, is half-duplex: it can either send or receive data at any one time but can’t do both.
RS-232 has a limited data transfer capacity: 20kb/sec maximum. RS-485 can handle up to 10Mb/sec.
RS-232 and RS-485 Info Resources:
Books About Computer Networks
Networking All-in-One Desk Reference For Dummies
Computer Networks (4th Edition)
Network Know-How: An Essential Guide for the Accidental Admin
Computer Networks and Internets (5th Edition)
Network Warrior: Everything you need to know that wasn’t on the CCNA exam