Vista VDC1604, Инструкция по эксплуатации, Страница: 10 / 40

Page 10
VDC1604 VISTA DOME CONTROLLER Installation and Operating Instructions
INSTALLATION
This connection toplology is know as ‘Daisy-chain’. The following rules must be observed:
1. A maximum of four keyboards can be connected.
2. The distance from
A to F must not exceed 1200m (including the stub lengths).
3. Keyboards 1, 2, 3 and 4 will each require a separate PSU even if the total length of the RS485 network is less than 10m.
4. Cables
A - B , C - E and D - F are screened/shielded Cat5, and are available from Vista in lengths of 1m up to 10m.
The standard baud rate for the VDC1604 is 9600 bps which, together with line impedances, will restrict the cabling
distances for the keyboard. Approved RS485 cable should be used for the data connections between the NAPs. In theory,
cabling distance can be up to 1.2 km. In practice however, the type of cable chosen, its routing, etc. will have an effect on
the maximum length that can be used.
The keyboard has built in network termination and/or biasing. For most small to medium sized installations, it should not
be necessary to change the switches from their default settings. Only for large installations should your network require
biasing and/or terminating. The switches are shown below. The default setting for switches 1, 2 and 3 is OFF. Switch 4 is
not used.
BAXKMI Network Access Point Connections
The interconnection of Network Access Points is shown in Figure 6.
Fig. 6 - BAXKMI Network Access Point Interconnections
4
OFF
UP
ON
3 2 1
*Default setting
Network setting Switch 1 Switch 2
Biased ON ON
Not Biased* OFF* OFF*
Network setting Switch 3
Terminated ON
Not Terminated* OFF*
*Default setting