I-O Display Systems Basic I/O Product manual RS-485 can only be multidrop, Repeat

Setup & Installation 2

BASIC I/Os can be networked together to obtain up to 4096 I/O points of data. These serial networks can be either multidrop or repeat.

Figure 2-3 Multidrop V.S. Repeat networks

Multidrop:

Multidrop networks can be up to 5000 ft long end-to-end.

Each station is passively located on the network and represents one “Drop” or load to the host communication driver.

A multidrop network will tolerate loss of power to any one station without effecting the rest of the network..

RS-485 can only be multidrop

Signal boost may be necessary depending on line conditions and number of drops.

Repeat:

Repeat networks can be as long as 5000 ft between each unit.

Each station plays an active role in communications to other units. If power is removed from a unit in a repeat network, communications to units “downstream” from it will be lost as well.

2-4(Vol.1)