Upstream Communication - Lenel OnGuard Hardware Installation Manual

LNL-1320-U Dual Door Controller Module
Install the resistors (provided with the module) as close to input device as possible. For cable length
limitations, refer to the Specifications
Input Resistor Table
Normal
Alarm
Fault - Line Short
Fault - Line Open
Fault - Foreign Voltage
88.2

Upstream Communication

The DDC uses Port 1 to communicate to the Intelligent System Controller.
Port 1 is a 2-wire RS-485 interface, that requires the following type of RS-485 cable: 24 AWG (minimum)
twisted pair (with shields). The main run RS-485 cable should be no longer than 4000 feet [1219 m], 100
ohms maximum (Belden 9841, West Penn, or equivalent). The drop cables (to downstream devices) should
be kept as short as possible, no longer than 10 feet [3.048 m].
The RS-485 communication is asynchronous, half-duplex, using 1 start bit, 8 data bits, 1 stop bit.
Note: RS-485 communication is supported for upstream communication only.
442 —
revision 7
section.
Alarm Zone Contact NC
1K ± 10%
2K ± 10%
0 - 50
∞
15K -
50 -750
1250 -1500
2500 -15K
DDC upstream communication
Alarm Zone Contact NO
2K ± 10%
1K ± 10%
0 - 50
∞
15K -
50 - 750
1250 - 1500
2500 -15K