ADT FOCUS 200 PLUS Installation And Setup Manual page 91

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Each ACIU draws 60mA (including battery charge). Similarly, each card/key reader (or Keylok)
draws a current that is specified in the Equipment section. These current draws affect the overall
system power requirements; therefore, they must be incorporated into the power calculations in
the Power Requirements section.
When you are calculating power requirements, make sure that each ACIU will receive a minimum
of 8.5 volts (the same as the gateways and operating panels). This is based on 10.5 volts being
supplied by the control unit battery with all sensors in alarm, and is calculated based on voltage
drops on the RS-485 bus. The 8.5 volts cannot be measured; however, when the power transformer
is plugged in, the ACIU should be receiving 12.5 volts from the RS-485 bus in order to recharge the
on-board battery. This voltage can be measured.
Note: The current for operating the door strike is furnished by the battery in the ACIU or by an
external power supply, and does not enter into these calculations.
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Where an operating panel is being used with an ACIU for access control, it must be assigned
communication Group # 0 on the RS-485 bus. All other operating panels that are not being used for
access control must be assigned to communication Group # 1. The purpose is to prevent access
control operating panels from being locked out if someone else is using a non-access control panel
for a period of time, and visa versa.
RS-485 Buses
Each gateway connects to a port in the control unit via a cable known as an RS-485 bus. The control
unit can accommodate two independent RS-485 buses of 4000 feet each permitting an end-to-end reach
of up to 8000 feet if using both buses. The total end-to end reach can be extended to 16,000 feet by
using a 472430 RS-485 Repeater at the end of each bus. Current loading and voltage drop
considerations may limit the maximum allowable wire lengths on each RS-485 bus to less than 4000
feet. See the Power Requirements section for additional information.
RS-485 Bus Cable Types
Two types of bus cable are used. Each is a 4-conductor multi-gauge cable, differing only in the type of
insulation.
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494465 (B6445) Cable - used as general purpose.
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494467 (B6467) Cable - used specifically in air handling plenums.
Cable Run Considerations
The safeguarding of RS-485 bus cable(s) from physical damage is vital to continuous uninterrupted
operation of the FOCUS 200 PLUS System. Keep the following guidelines in mind when running the
cable:
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Bus cable(s) should be routed to take advantage of the shortest possible length of cable to minimize
voltage drop.
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Any junction boxes (test terminals) that are required can be placed to be accessible from the floor.
Junction boxes can also be used to sectionalize the bus to aid troubleshooting.
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Each of the buses is terminated internally in the control unit and so there are no bus terminating
jumpers on the control unit circuit board. This means that neither of the buses by itself can be used
in a dual run configuration (two runs from a common connector).
Mounting the Access Control Interface Unit
To mount the ACIU, perform the following steps:
Step Action
1 Locate the ACIU close to the door that it will be used with. Choose a spot inside the
protected area, where it will not be susceptible to tampering or to damage due to the
moving of office furniture, machinery, etc.
2 Mount the 472352 Housing Unit (standard white PID box).
3 Set the Jumpers E2 through E9 for the appropriate address on the RS-485 bus (all ACIUs
use communication Group number 4).
4 Set Jumpers E1, E10, and E11 as required.
Section 10 – Access Control
10-5