I-O Display Systems Basic I/O Product - Manual (Page 21)

Setup & Installation 2
2-4(Vol.1)
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.