DDAA1000/SRM User Guide

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

DC Supply

+ -

Dry Contact Closure

8 7 6 5 4 3 2 1 G

8 7 6 5 4 3 2 1 G

Contact Closure Input

Contact Closure Output

Master

8 7 6 5 4 3 2 1 G

8 7 6 5 4 3 2 1 G

Contact Closure Input

Contact Closure Output

Remote 0

DC Supply

+ -

8 7 6 5 4 3 2 1 G

8 7 6 5 4 3 2 1 G

Contact Closure Input

Contact Closure Output

Remote 1

PN 161-09981-002C

rev 8/04

DATA-LINC GROUP

7

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Omron DDAA1000/SRM manual Point-to-Multipoint Discrete Operation, Master