I-O Display Systems Basic I/O Product - Manual (Page 63)

Installation 2
2-9(Vol.2)
The three basic communication connections for individual BASIC I/O ADs are:
Repeat
Used in RS-422 networks to extend range
to 5000 feet between units. Sequential
Display reads L1
Multidrop
Used in RS-422 or RS-485 networks.
Provides a total network range of 5000 feet.
Display reads L2
Last Unit
Must be used in RS-422 and RS-485
networks for the unit most distant from the
host. Sequential display reads L3
If there is only one BASIC I/O AD in a network it is designated L3.
For the network layout, the sequential display indicates the letter “L” followed by “1", “2", or
“3". As shipped, BASIC I/O ADs are setup as “l3", Last Unit. This parameter is not changed
by push button but is displayed as “l1", “L2", or “L3" after the dip switches have been set and
the unit has undergone a power cycle.