User Manual

Alarm management

Effects of BACnet properties on alarm response

140 | 353 CM110664en_07

and Close. The first end switch, the Open switch delivers the signals Fully open

or Not fully open. The second end switch, the Closed switch delivers the signals

Fully closed or Not fully closed. The following is an example of how to connect

the BO (binary output for commanding and integrating the Open switch) and BI

(the binary output for the closed switch):

Given the feedback signal [FbVal] Fully open, the Open and Close commands

follow the time sequence shown below, making use of all three deviation

monitoring times [TiMonDvn].

Since the BO block can handle the feedback of two different addresses, the

fire-protection damper solution can be further simplified by direct connection of

the Closed switch (Addr. 1) and Open switch (Addr. 2). In cases where both end

switches are simultaneously On or simultaneously Off, the BO block treats the

[FbVal] as invalid. Throughout this period, therefore, the alarm monitoring

function will return the value Alarm = OFFNORMAL. The circuit and time

sequence for normal and error conditions are as follows:

Circuit and time sequence for normal and error conditions: