Fire-Lite ACM-32AF Annunciator Modules - Manual (Page 48)

Appendix B: Sensiscan 2000 Connecting the EIA-485 Circuit
48
ACM-16ATF/ACM-32AF Manual PN 51480:A0 02/02/01
Connecting the EIA-485 Circuit
Communication between the control panel and the annunciator module is
accomplished over a two-wire EIA-485 serial interface.
• Power-limited and supervised.
• 6000 feet maximum distance (with 16 AWG wire) between the control
panel and the furthest annunciator.
• Use twisted pair cable with a characteristic impedance of
approximately 120 ohms.
• EIA-485 circuit rated 5.5 VDC max., 60 mA max.
This communication circuit is supervised by the Sensiscan 2000. Loss of
communication results in “System Trouble” and “Module Failure”
indications at the CPU.
Note: “System Trouble” and “Module Failure” will also occur if the normally closed
supervisory path between TB1 Terminals on the annunciator is opened (or the
jumper has not been installed).
The EIA-485 circuit is connected between the EIA-485 Interface on the CPU
and terminal TB2 on the annunciator.
Figure 20 EIA-485 Circuit Connections - Sensiscan 2000
– +
A
C
S
f-s2
00.cdr
EIA-485 Interface
on CPU of the
Sensiscan 2000
TB2