Technical Manual - Tunstall GmbH

8. Laying cables
8.6 Secondary lines (code: a)
Ward bus
66
19 0700 20
The cable system with room devices that is connected to a defined input of a
room terminal is designated as a secondary line. Room terminals are Terminal
SD6 P, Terminal S4 P, Terminal S4 B, the display module and the call/presence
combination bus (RAB). The number of secondary lines, i.e. the number of in‐
puts of a room terminal, depends on the devices and can be found in the room
terminal's product leaflets.
Room devices that are connected to the secondary lines are:
Room lamp
All switches
Call switch with connection socket
Call switch with 2 connection sockets
Sensor mat with free cable ends
Smoke detector
The cable type for secondary lines is ”a”, i.e. a standard telecommunications
cable IY(ST)Y 2x2x0.8 mm.
Note! Switches with 2 buttons, e.g. the call & cancel switch/WC, order
no.19 0708 50, are connected differently to all other room devices with the ca‐
ble type ”c”, i.e. a standard telecommunications cable IY(ST)Y 4x2x0.8 mm.
Each room device (apart from the room lamp) must be terminated with a
120 kOhm resistor. Even when several room devices are connected to one
defined secondary line, each of these devices must be terminated with a
120 kOhm resistor. The resistor is already present in the devices. Refer to the
product leaflet for the respective device for details of how to activate the termin‐
ating resistor.
Note! The maximum permissible cable length of each secondary line is 20 m
in total. A maximum of 4 room devices may be connected to one defined secon‐
dary line, i.e. at one input of a room terminal.
a
Secondary line
Secondary line
Secondary line
Secondary line
a
77 0180 10
4x2x0.8
a
19 0708 50
19 0704 00 19 0704 00
a a
19 0708 00
a
19 0704 00
19 0707 20x
19 0704 00
CONCENTO PLUS - Technical Manual, 11/12 (Rev. 3.0), 00 8814 14