ADT FOCUS 200 PLUS Installation And Setup Manual page 122

FOCUS 200 PLUS Installation and Setup Guide
Table 3: RF Gateway & RF Receiver Standby and Alarm Loads
Device
RF Gateway
RF Receiver
(maximum 2)
Total Gateway & Receiver
Standby and Alarm Current
To calculate the standby and alarm loads for each gateway, perform the following steps:
Step
1
2
Drawing Load Diagrams for the RS-485 Buses
Step
1
2
3
4
12-4
Gateway Unit No. 7 (Max. 72 Points)
A
Standby
Quantity
Current (mA)
1
Standby
Action
Make a copy of each table for each gateway on the system.
Fill in Tables 1, 2, and 3 to calculate the standby and alarm current loads for each
gateway. Use Table 1 for PID Gateways, Table 2 for SIM Gateways, and Table 3 for RF
Gateways. These totals will be used to determine the gateway trunk cable lengths and
the size of the system's backup battery.
Action
Using the Load Diagrams shown in Figures 12-1 and 12-2 as an example, make a similar
diagram showing each device (gateway, operating panel, etc.) along each RS-485 bus.
Estimate the cable distance in feet from the control unit to the first device on the bus,
and also the distance between devices. Then, mark the distances on the Load Diagram.
Enter the total alarm load that each operating panel and gateway present to the RS-485
bus. Enter this data in the appropriate boxes that represent the operating panels (use
65mA for each) and gateways (total from the previous tables).
Record, on the Load Diagram, the current that will flow through each section of the RS-
485 bus using the following information:
a. The current through the first section of the bus is the sum of all loads presented by
the operating panels and gateways.
b. The current through the second section is the sum of all loads (obtained in item (a)
above) minus the load for the first gateway, operating panel, or other device on the
bus.
c. The current through the third section will be the sum of all loads minus the loads for
the first and second devices on the bus.
B AxB
Total
Standby
Current (mA)
50 50
60
C AxC
Alarm Total Alarm
Current Current
(mA) (mA)
50 50
60
Alarm