ADT Security Services ADT-LCD40 - Manual (Page 22)

ADT-LCD40 Series Electrical Connections EIA-485 Connection
22 Document 50520 Rev D 7/25/00 P/N 50520:D
Notes:
1. All connections are power-limited and supervised
2. A maximum of 32 ADT-LCD40 Series annunciators may be con-
nected to this circuit
3. 6,000 feet (1,800 m) maximum distance @ 18 AWG (0.75 mm 2 )
between the panel, annunciators and return to the panel.
4. Use overall foil/braided-shielded twisted pair cable suitable for
EIA-485 applications (refer to “EIA-485 Shield Termination” on
page 25, for shield termination information)
5. The EIA-485 circuit is rated at 5.5 VDC maximum and 60 mA
maximum
6. The ADT-LCD40 Series annunciators have resistors built into
the circuit board at the In (Terminals 2 & 4) and the Out (Termi-
nals 1 & 3) for impedance matching. There is no need for the
installer to add impedance matching resistors
Figure 4-2: EIA-485 Connection
Terminal Block replacement
P/N 02108
P1 P2
Terminal Block
replacement
P/N 02109
(+) (-)
EIA-485
Out to next ADT-LCD40 Series
or return to host FACP if last or
only annunciator on line
+ EIA-485 IN from source
- EIA-485 IN from source
ADT-LCD40 Series
6,000 feet (1,800 m) maximum wire run
from and back to FACP (3,000 feet to last
ADT-LCD40) @ 18 AWG (0.75 mm
2
)