How to connect DVR to a GSM Dialer for notifications

[twister0009 0]

Hi everyone,

I have a question and please help me as you can.

I want to connect my DVR with a universal GSM dialer, in order to get notifications if something is wrong.

I know with power cut it can be done but how can i connect the GSM to get notifications for Video loss.

The DVR Cant be networked because its located in a field with no internet access.

I know the DVR makes a beep noise when there is a power loss , so my question is , can i use that circuits voltage closing to trigger an input of the GSM?

Can anyone help please?

[Dontheo 0]

It really depends of the equipment including your GSM. What type of input does the GSM have? You would need to measure the voltage to the buzzer possibly take that to a relay that would trigger the GSM.

[gmcraib 0]

Logic wise its fairly simple if you understand 'relay logic'.

You can get GSM diallers that work with alarm systems and they have a simple contact trigger. I think you can get both N/O and N/C inputs on them and you can connect depending on output from DVR.

But even if you have non-straightforward connections you can work around with an interposing relay.

 

Problem is, if you are wanting to signal on loss of power how can you be sure the signal will work?

ie if output from DVR is high on alarm you will not get a power loss signal as there will be no power to drive the signal.

If its low on alarm or 'volt free' (ie switch only) then you are ok.

 

The interposing relay can be used to switch the logic if needed (like a NOT gate in electronics) ie a coil energised with a N/O switch can have N/O and N/C switches, so using a N/C inverts the logic.

 

Say for your system the output from DVR goes low (or opens) to the interposing relay coil when in alarm. You have connected the interposing relay N/O output to GSM dialler so upon loss of volts the contact is closed and the GSM sees a signal even though the DVR is dead.

This obviously needs a power supply to relay but so will GSM dialler and I'm assuming that is in the house.

 

If not you may be able to get a small 12V battery to power the relay and dialler and this can be recharged by the same power supply to DVR.

 

Many ways to skin a cat, like the previous poster said it depends on what you have but nothing is impossible when it comes to relays and logic!!

 

Another problem you may want to avoid - particularly if your relay and GSM are not in the field is voltage drop on the cables. Long/thin cables drop the volts, possibly to the point where an energised coil and N/C contact appears to be open because the volts have dropped below a threshold or the coil itself cannot energise because of the same reason (prob 80% of coil voltage)