Sharp JW-20CM User Manual page 54

From the previous page
Set STA. NO. (station number) switch
· Set "STA. NO" (station number) in octal
notation in sequential numbers from 01 to 77.
Be careful that there is no doubled setting or
l a c k e d n u m b e r s e t t i n g . ( N u m b e r o f
connectable slave stations: See page 8·2)
Set LT (termination resistance) switch
• When a JW-20RS slave module is at either
end the communication line, make sure to
set the termination resistance switch "ON."
Reference: Function of the termination resistance switch
If the communication line does not have a termination resistance, the high frequency signal will
be reflected at the ends of the cable. These reflected signals can collide with the original
8
communication signals, so that some stations will not be able to communicate normally. The
use of termination resistance suppresses reflected signals. If the termination resistance switch
on any of the stations in between the end of the cable is turned ON, the station will generate a
reflection wave signal or attenuate the original signal and may not communicate normally.
· When the trunk line has a branch in it, turn ON the termination resistance at the station on the
trunk cable.
· If you use a terminator (termination resistance made by Toko Denshi: ME-75) at the end of a
signal cable, turn OFF the termination resistance at the station on the end of the cable.
To the next page
Turn ON the termination resistance
switches on these two stations.
Termination
Drop cable
resistance (ON)
(branch line should
be less than 400 mm)
Trunk cable
Terminator
Less than 1 km
Terminator: ME-75
8
STA.NO.
(ON)
(ON)
16
·
×10
×1
L T
L G
"T" branch
Terminator