Installation guide

MODEL 1020 DUAL LEM (D-LEM) cont

The D-LEMs may be placed in any order and in any position on the cable. There is no restriction

on the distance between D-LEMs. The end of the cable does not need to be looped back to the

control unit; however, if convenient, you may install a "round-robin" LEM line terminated back

again in the APLEX control panel. This will allow continuous operation of the system with a

single break in the LEM line and easier trouble-shooting for service personnel.

MODEL 1020 D-LEM CODING

The Model 1020 D-LEM is addressed by coding the Dual-in-Line (DIL) switch on the printed

circuit board. There are eight individual numbered switches. In the up or ON position (towards

the centre of the PCB), each switch number has a value zero (0); in the down or OFF position

(towards the edge of the PCB), each switch number has a different decimal value. The decimal

value is displayed in the chart below:

Switch No.: 1 2 3 4 5 6 7 8 ON = 0, OFF = Dec. Value

Decimal Value: 128 64 32 16 8 4 2 1

The sum of the decimal value for all switches in the down (OFF) position is the address for that

D-LEM unit (e.g., Switch numbers 6 and 8 down would be address 5; i.e., 4 + 1).

There are two zone inputs per D-LEM unit; therefore, the zone number is calculated as follows:

ODD NO. Zone (input terminals 7 & 6) = (LEM address value x 2)-1

EVEN NO. Zone (input terminals 5 & 6) = LEM address value x 2

For example: The D-LEM unit above, coded to address 5, monitors zone inputs 9 and 10. The

tamper micro switch on the D-LEM printed circuit board is in series with the even-numbered

zone input, in this case, zone 10. If the zone is on line and the tamper is opened, a disconnect

signal will be received by the panel. The APLEX panel will display AREA-1 10 DISCON. On

initialization, the system will only recognize inputs that are not in the disconnect state (i.e., input

loops with continuity); therefore, be sure that the covers are on the D-LEM units if the even-

numbered zones are expected to function.

IMPORTANT NOTES:

1. No two D-LEM units may have the same address on the system. There is just one exception to

this rule. If only one zone input is used on one D-LEM unit (say, zone 12 using terminals 5 to 6),

leaving the second zone input open circuited, then the second zone input (say, zone 11 using

terminals 6 to 7) may be used on the other identically addressed D-LEM unit, leaving its first

input open circuited.

MODEL 1020 DUAL LEM (D-LEM) cont.