DATA-LINC GROUP
7
DDAA1000/SRM User Guide
PN 161-09981-002C
rev 8/04
Point-to-Multipoint Discrete Operation
A multipoint system will involve two or more remote locations, which may be transmitting contact input information,
providing discrete outputs or both. The following is an example of a multipoint configuration.
In this example, the Master is transmitting a contact closure input to both Remotes. Note that input #1 on the Master will
trigger the same numbered output on all Remote units at the same time.
Since there are more remote inputs than master outputs, the contact closures at the Remote inputs are ‘OR’d at the
Masters outputs. The closure of any Remote input will cause the Master output to be On (sinking current). If any Remote
input is closed the Master output will be On for that position. For the Master output to be Off, all Remote inputs must be
open (Off).
Figure 5: Point-to-Multipoint Discrete Operation Example
Contact Closure Input
Contact Closure Outp
ut
8 7 6 5 4 3 2 1 G
8 7 6 5 4 3 2 1 G
Contact Closure Input
Contact Closure Outp
ut
8 7 6 5 4 3 2 1 G
8 7 6 5 4 3 2 1 G
Contact Closure Input
Contact Closure Outp
ut
8 7 6 5 4 3 2 1 G
8 7 6 5 4 3 2 1 G
Dry Contact Closure
DC Supply
+ -
DC Supply
+ -
Master
Remote 0
Remote 1
