Up/Down Keys; Channel 4 And Vtr Trigger; Alarms; Alarm Contact Types - Videotec SW164OSM Manuel D'instructions

3.1.4 Up/Down keys

Up/Down keys on DCS2 and KEYPLUS keyboards will suspend a sequence on one input and
allow selection of the next/previous (according to the order defined by the switching cycle in
progress) video input without using the numeric keypad.

3.1.5 Channel 4 and VTR trigger

of the trigger itself. Any command which may be sent from the keyboard will be therefore
neglected.
3.2

Alarms

The matrix features a DB25 connector, where 16 alarm contacts can be applied ("alarm inputs").
When an alarm is activated :
• the keyboards show the ALARM led blinking and activate a warning buzzer
• each output enabled to recognise an alarm automatically starts the respective sequence cycle (if set
as "active").
• a relay is closed (auxiliary contact on DB25) and a warning buzzer inside the matrix is activated
• the "ALARM" text is added to the input identification text.
An alarm condition is internally stored and is kept even if SW164OSM power supply is cut-off.
Caution! The alarm configuration must be carried out with great care, since incorrect adjustment of the
alarm parameters may lead to misoperations difficult to identify.

3.2.1 Alarm contact types

Each single alarm contact can be defined as :
• normally open (N.O.): the alarm condition is recognised when the alarm pin is connected to the
alarm common pin
• normally closed (N.C.): the alarm condition is activated when the contact between the alarm
pin and the alarm common pin is interrupted
• not used : the alarm pin is not considered. The pins which are not connected to any alarm
contact must be configured as NOT USED.
Please, refer to the following example to
understand the operation of the alarm
contacts :
Normally open: the contacts are
disconnected from the alarm common.
When the contact is closed, alarm 3 is
acknowledged.
Normally closed : the contacts are
connected to the alarm common (pin 25).
When the connection opens alarm 1 and 3
are activated.
If the VTR trigger is enabled, the control of the channel 4 is only subject to the impulse
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