JVC VN-A1U - Network Encoder Instructions Manual page 18

● Summary of alarm input/output functions
Interlocked alarm
triggered by alarm
input
Interface condition of ALARM INPUT terminals
Non-voltage relay "a" contact input
or non-contact semiconductor "a" contact input
or NPN open-collector input.
Active low level, latch/momentary (500 ms or more)
Circuit current at Low level: 0.6 mA. Applied voltage at High level: 3.3 V.
Sensor devices
Infrared sensor, door sensor, metal sensor, manual switch, etc.
Interface condition of ALARM OUTPUT terminals
NPN open-collector output or equivalent (The output logic is set by the
Controller.)
Allowable input voltage: 12 V DC or less
Allowable current drain: 300 mA or less
Momentary (2 to 5000 ms) output (The time period is set by the Controller.)
Examples of alarm devices
Alarm, indicator, lamp, buzzer, etc.
* The types of relay contact mechanisms are expressed as "a" contact, "b"
contact, "c" contact, etc.
"a" contact: The contact is normally Open and is Closed when an event
occurs.
"b" contact: The contact is normally Closed and is Open when an event
occurs.
"c" contact: The contact status is inverted every time an event occurs.
18
VN-A1U
1.2
3.3 V
G
OUT
MAX.300 mA
COM
G
OUT
0.6 mA
GND
Sensor device
IN
MAX.12 V
COM
GND
Alarm device