Bosch Divar -Digital Versatile Recorder - Manual (Page 36)

Bosch Security Systems
Divar | Installation Manual | Hardware setup EN | 4-4
Keyboard connections
The keyboard input and output connectors are used to connect an external
keyboard to the unit. Connect the keyboard to the KBD IN connector. Up to 4
external keyboards can be connected when the optional keyboard port
expander (LTC2604) is used.
For short distances (up to 30m), standard 6-core telecom flat cable can be used
to supply power and signal connections for the keyboard.
For distances over 30m between keyboard and Divar, the Keyboard Extension
Kit (LTC 8557) must be used. This kit provides junction boxes, cables and the
appropriate power supply for the external keyboards. The recommended cable
type is Belden 9841 or equivalent.
Divar connection
The KBD IN and KBD OUT connectors can also be used to connect several
Divar units to each other. The loop-through connector arrangement allows easy
interconnection of up to 30 Divars. The connection uses RS485-based
communications.
The RS485 connection is not galvanically separated. If you have an installation
where Divars are connected via RS485 and they are not located close to each
other, you must ensure that they are grounded via the same, clean grounding
wire.
Specifications
Communicaton protocol: RS485
Maximum signal voltage: ± 12V
Power supply: 11 - 12.6V, maximum 400mA
Maximum cable length: 1.5 kilometers
Cable type: black (cross-over) cable (supplied with keyboard)
Termination: 390 Ohm terminator
Keyboard In - RJ11 socket (KBD IN)
Keyboard out - RJ11 socket (KBD OUT)
Pin no. Signal
1 +12 V DC (11V Min to 12.6V Max, 400mA Max)
2 System ground
3 Keyboard plus line
4 Keyboard minus line
5 System ground
6 System ground
Pin no. Signal
1 No Connection
2 System ground
3 Keyboard minus line
4 Keyboard plus line
5 System ground
6 No Connection
6 1 4 2
Panel view