Connecting Contact Alarms to a Unison System
7-48
InterReach Unison Installation, Operation, and Reference Manual
CONFIDENTIAL
D-620003-0-20 Rev J
• The micro controller sees a high or 5V for an open condition. The loop resistance
must be greater then 20K Ohm to guarantee the micro sees 3.5V or greater.
• The micro controller sees low or 0V for a closed condition. The loop resistance
must be greater than 2K Ohm to guarantee the micro sees 1V or less.
• You may have to determine a time on and off for the connection so that the alarm
is not intermittent.
• Firmware has a five second hysteresis to ensure the micro does not capture inter-
mittent contact closures.
Table 7-12
Output Electrical Characteristics
I max is 5V/10K = 500uA. +/- uA due to R and V tolerances.
Vmax is 5V+5% from power supply spec.
Parameter
Description
Specification
I Max
Continuous Load Current
550uA
V Max
DC volts out
5 V + 5%
T on Max
Max Turn-on Time
5 Seconds
T off Max
Max Turn-Off Time
5 Seconds