2-2b. CCTV with relay - Event Handler (solution)

System configuration

Solution

Call buttons:

• Pressing the call button at the Entrance or at the SOS Point should generate a call in private ringing mode to the Control Room.

Program DAK 1 of the Entrance station to "I 101"

Program DAK 1 of the SOS Point station to "I 101"

By setting Call Priority Setup = Low, the call from the Entrance will be forced to Private ringing mode, regardless of the Open/Private status of the Control Room

By setting Call Priority Setup = Low, the call from the SOS Point will be forced to Private ringing mode, regardless of the Open/Private status of the Control Room

Relay control

• A relay output to the CCTV system should be activated when the private ringing starts. There is one relay for each substation. Use the outputs 5 and 6.
• The relay should stay activate until the call is accepted and the conversation is cancelled. (If the call is not answered, the relay must drop when the ringing times out).

When the Control Room starts ringing (The Private Ringing mode event goes ON), and the caller is station 107, turn on RCO 5:

Private Ringing mode ON at 101 when called from station 107 will trigger RCO 5 on

When the Control Room starts ringing (The Private Ringing mode event goes ON), and the caller is station 108, turn on RCO 6:

Private Ringing mode ON at 101 when called from station 108 will trigger RCO 6 on

When the conversation with the Entrance ends (or the ringing times out), the station returns to idle mode. Now the event "4 - Station in Use" will go OFF:

Turn off the RCO 5 when the Entrance station 107 returns to idle

When the conversation with the SOS Point ends (or the ringing times out), the station returns to idle mode. Now the event "4 - Station in Use" will go OFF:

Turn off the RCO 6 when SOS point station 108 returns to idle

Relay control. Alternative solution

This solution reduces the number of events. Instead of using one event for each substation, one can set the "When Related To" = "All", and use the IF statement to check who is calling.

This event is triggered by calls from any station. The IF statement is used to check who the caller is

Action string:

IF %op(%2.dir,=,107)
RCO 5 ON
ENDIF
IF %op(%2.dir,=,108)
RCO 6 ON
ENDIF

Explanation: If the call is from 107, turn on RCO 5. If the call is from 108, turn on RCO 6.

When the Control Room station returns to idle, the outputs should go off:

Turn all outputs off whenever the Control Room returns to idle

---

Related articles

• 2-2b. CCTV with relay - Event Handler (practice)