Home 10 zone monitor/alarm system using SNMP ethernet hubs.

This is my first instructable, so hope is of interest.
This 10 zone monitor or alam system,  is done using a low cost IP snmp hub and Windows based PC running snmp software from commercial outlet but in freeware 10 node version. You can have as many zones as you have snmp ports, the restriction is the freeware version of "serversalive" product I have used. The instructions below are for 6 ports, just duplicate for more zones etc.

I devised this system to help ensure various doors, fridges etc in house where closed/ locked as my young childern kept leaving them open ?

This software can raise many alarms from windows popup and email to IQU among others. The software also has schedule software so you can have automatic polling of zones, and each zone can have different alerts. The alerts can be seen on pc or as web pages.

I have used a 3Com PS40 24 port ethernet hub which has SNMP built in, but have tried on various Cisco Nortel and others. The instructable will help you build the interface and guide you through getting the Windows PC (XP) talking to unit and which options to poll etc.

Step 1 What you will need for this home 10 node monitor system

You will need below items

1 x 3com PS40 12 or 24 port hub, (3C16406) can get from ebay from £10
Windows XP internet PC
4 x 12 way electrical connector blocks
1 x 2m red cat5 utp cable
 1x 1m blue cat5 utp cable
1x 1m grey cat5 utp cable
1x 1m yellow cat5 utp cable
Door reed switches as used in alarm systems, or limit switches.

Servers alive software from download page

http://www.woodstone.nu/salive/download.asp

Comments

[Scheer]

Thanks for the reply. I am using cross-connect cable which may be my problem as it is not twisted as much as Cat5.

The timer relay is exactly what I am looking for, but it says that it is 12 volts. Will it damage the switch by injecting too much power?

Also, I am going to be upgrading the switches soon to Adtran Netvanta 1224 STR's, have you ever messed with them to know if the settings will be similar or not?

Thanks for the help, Taylor.

[sdurham]

Scheer

If you check link below, you can power the relay from the AUI port, as 3com hub has one of these on rear, if you need I can build you cable for small charge? or even to a timer relay module if need.

http://www.interfacebus.com/Connector_AUI_Ethernet_Pinout.html

I have no knowledge information for Adtran, you will need to know the MIB object for the interfaces, the MIB should be available from the Adtran Web site.

Hope it helps
Steve

[Scheer]

Thanks for the instructable, I have mine wired up and everything works when I test it with short wires, but I'm running into problems if I have more than 3m of wire between the switch and the reed switch. It is wired so that when the door is closed it will be open, and when opened it will close the circuit. But if I have more than 3m of wire the circuit is always closed, even when I do not connect the reed switch and the wires are not touching.

I have It works fine with short lengths of wire, and I have tried several different kinds of wire. Any ideas?

Also is there anyway to keep a switch open for 1 minute? The update time on servers alive is 1 minute and I would like for it to tell me when doors are opened. The only way it works right now is if a door is propped open, or they happen to open the door right when servers alive is doing is check.

[sdurham]

Scheer, Thanks for trying it. I have had similar problems depending on type of cables used from connector to limit switch. I used cat5 cable and used the same twisted pair (white/blue pair in photo) if still have problem try using a second limit switch in the "closed" loop part of circuit, this will ensure both parts of the loop are broken at same time.

You can also use a timer relay to give you the "latch for 1-3mins) so servers alive can poll in its normal 1 minutes period and catch the "door opened" state, see below item I have used for this feature. Connect so limit switch controls the "pulse" and the relay contacts switches the UTP port on 3Com hub.

http://cpc.farnell.com/1/1/31223-1s-3min-timer-i-1-cebek.html

Hope it helps
Steve