A-14
AFP-400 Installation
PN 50253:A2 03/12/96
ACS and LDM Series EIA-485 Connection
The circuit is power limited and supervised.
You can connect up to 10 devices to this circuit (such as ACMs, LDMs, and
AFMs).
Maximum distance between the control panel and the furthest annuncia-
tor: 6000 feet (@16 AWG).
Use twisted pair cable with a characteristic impedance of approximately
120 ohms.
An EIA-485 circuit is rated 5.5 VDC max., 60 mA max.
Refer to the ACS Manual and the LDM Manual for additional information.
Connection Guidelines
Connect ACS and LDM series devices to the CPU-400 as follows:
1) Set SW2 on the control panel to the ACS position.
2) Install a 120-ohm terminating resistor on the last annunciator in the
series of connections.
ACS and LDM Series
EIA-485 Connections
4
3
2
1
() EIA-485 In
(+) EIA-485 Out
() EIA-485 In
(+) EIA-485 Out
4
3
2
1
() EIA-485 In
(+) EIA-485 Out
() EIA-485 In
(+) EIA-485 Out
TB2
TB2
CPU-400
Figure A-5 ACS and LDM Series EIA-485 Connection
120-ohm terminating
resistor
