The resistors and diodes should be on each device.

I like the Schottky-Diode Termination method because it allows you the have a "Star" configuration on the 485 buss, and it uses less power than other methods.

Other types of termination require the devices to be in a line with a single termination at the farthest end. This is not always practical, and invariably the farthest end device gets disconnected somewhere along the way, and there goes your termination. Unless someone remembers to terminate the next farthest device. (never happens)

See figure 6 in this page for the diodes.
http://www.maxim-ic.com/appnotes.cfm/an_pk/1090
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