41(57)
Datum/Date
Rev
Dokumentnr/Documentnr
Uppgjord/Prepared
Dokansv/Godkänd - Doc respons/Approved
Kontr/Checked
Tillhör/Referens-File/Reference
1999-07-15
V
1531-BDV 113 08 Uen
INSTALLATION INSTRUCTION
Faktaansvarig - Subject responsible
6.7.3
Base station cable delay measurement
After all base stations have been installed, the cable delays must be measured in order to program the base station
delays into the system at initialization time. On IC-LUs with the revision R1D and higher and IC-CU2 revision R1C or
higher automatic delay measurement is performed. In this case no measurement is needed but using the cordless
system manager (CSM) go to the menu "add Base Station" and enter a "1" in the field "delay".
Base station delays are measured at the radio exchange with an echo-meter connected to cable data pair SC0 or SC1
and with the cable open ended at both sides. So the cable must be disconnected from the IC-LU or IC-CU2 as well
as the base station.
1.
Make sure that the base station cable is unplugged from the base station and the relevant connector on
the relevant IC-LU or IC-CU2.
2.
Connect an echo-meter to cable pair SC0 or SC1.
3.
Measure the cable delay. The measured delay is the time between sending a pulse down the line and
receiving the echo. Therefore the recorded value is twice the cable delay and must be halved. The
resulting value must have an accuracy of 200 ns (corresponding with 20 – 30 m).
4.
Record on paper the delay value measured for each base station in microseconds, together with the
base station number.
5.
Repeat the delay measurement for all base stations.
6.
Re-connect the connectors to the IC-LU or IC-CU2.
Another possibility is measuring the ohmic resistance:
Connect to SC0 or SC1 measure the resistance of the loop and divide the result by 3,3. This is the value to be entered
at system initialization in the Cordless System Manager.
This formula applies for wires of 0.5 mm diameter. After all lines to the Base Stations have been measured, connect
the Base Stations by plugging-in the connector.
6.7.4
Ranges on cables
The following ranges are given for base stations connected to an IC-CU2 and IC-LU. Depending on the cable type
ranges depend on noise levels imposed on the cables. The values stated are maximum achievable ranges:
Type
Cable
Maximum cable length
Wire diameter (
∅
)
Capacitance
Superimposed noise
8
m
V/
p
Hz
10
m
V/
p
Hz
Twisted pair
0.4 mm
45 nF/km
1.2 km
1.0 km
Twisted pair
0.5 mm
45 nF/km
1.6 km
1.4 km
Twisted pair
0.5 mm
120 nF/km
0.9 km
0.8 km
Twisted pair
0.6 mm
45 nF/km
1.9 km
1.7 km
Twisted pair
0.6 mm
120 nF/km
1.1 km
1.0 km
Double twisted pair
(J-Y (St)Y 2
×
2
×
0.6)
0.6 mm
120 nF/km
1.0 km
0.9 km