User's Manual

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Page 16
EME149A-20
724-746-5500 | blackbox.com
Chapter 2: Overview
2.4 ServSensor with 20 or 60 Extra Dry Contact Inputs, VAC, or VDC
The 20 or 60 extra dry contact inputs on the ServSensor can be configured as inputs only up to 5 Volts in normal operation. In
opto-isolation mode they can input up to 30 Volts DC. This will protect these inputs and the unit from high voltages and spikes.
Opto-isolators provide complete electrical separation between the ServSensor and the dry contact. The base units are therefore
protected against possible large voltage spikes caused by lightning, for example.
The figure below shows the jumpers (on the dry contact board) set up to provide opto-isolators support.
Refer to the rear panel of the ServSensor above for the other connections on the rear panel, as they are exactly the same in
functionality.
Figure 2-9. Jumper settings.
The OID for the extra dry contact inputs is:- .1.3.6.1.4.1.3854.1.2.2.1.18.1.3.<port>
2.4.1 Extra Dry Contact Input Practical Applications
The extra dry contact inputs can be used to monitor many types of equipment, for example, you can run the connection from
warning lights on alarm panels to the dry contact inputs, so that when the warning light on the alarm panel is activated, the dry
contact is triggered in the unit’s Web interface, thus allowing you to send notifications via emails or SNMP traps.