How are dry contact closures useful? Well, an example would be an electromagnetic relay that starts a motor. When the motor starts, the dry contact changes states, as the mechanical action of the starter moves it. Dry contact switches can be set off by any number of things. For instance, dry contact solutions are often used with burglar alarms, smoke alarms, UPS, AC units and many more.

So how does Ravica tie into this? The SecurityProbe-x20 and SecurityProbe-x60 are how. If you hadn’t guessed, the “x” stands for the number of dry contact connections that are built into the units. The securityProbe-X20/60 comes with 8 full auto-sense RJ-45 ports, for connecting any of our intelligent sensors. An additional 20 two-wire dry contact ports are provided, giving a total of up to 28 dry contact ports. The specially designed two-wire dry contact ports are easy to use, and allow you to make your own dry contact cables quickly and easily.

The SecurityProbe systems support both normally open (NO) and normally closed (NC) contacts. This is a setting specified within the web interface.

If you have an existing security system or HVAC system, chances are it will integrate with the SecurityProbe-x20/60. When the attached switch changes states, the SecurityProbe instantly knows and can be configured to perform any number of given actions; from sending an email alert or an SMS message, to delivering an automatic shutdown command to your servers before they drain the attached UPS.

If you are a user of the BitSight line of sensor probes and are not ready to upgrade to the x20 or x60 line, but have a need for monitoring dry contact ports, then a single dry contact sensor may be exactly what you need. The individual dry contact sensors, because they attach to the the intelligent sensor ports, are able to operate in both input and output mode.

Dry contact sensors are sometimes referred to as “dumb sensors,” simply because with dry contacts everything is a “yes” or a “no.” But the openness and simplicity of the dry contact system make them anything but dumb to use.

~ Jon Mills
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