ZoneMinder Forums

Hi all,
i'm going to design the electrical schematic for an external alarm board for zoneminder.
The first goal is to allow zoneminder to switch on/off any device connected to the external board and and also read the status of the input (ir sensors, etc...)
Inputs/outputs will be interfaced with opto-coupler to provide electrical insulation between the pc running zoneminder in order to avoid damages from external devices.
The board will also be equipped with a 4 input/output video buffer and multiplexer (quad) and a com port (or usb) for the communication with zoneminder.
An ascii protocol will be used to send commands to the board.
The board will not support X10 protocol.
If you have some (reasonable) ideas please submit here your requests and i'll consider to embed it in the design of the board..
thanks.
bye

I don't know about the video quad stuff, but a pretty easy and inexpensive way to get 8-bits digital in, 8-bits digital out (TTL level, also has two 12-bit, 0-5V D/A outputs and two 12-bit 0-4V A/D inputs) running off 5V DC is the ~$35 WIZ220io:

http://www.saelig.com/BRD/BRD017.htm
Many other distributors stock it, if you search with Google.


The documentation for it that you download is just plain wrong, but I've posed a simple Linux udp query response test program after figuring out the data format by eavesdropping on the Windows config utility using Wireshark. You can find it here:

http://wizwiki.net/forum/viewtopic.php?f=60&t=228


Basically you send a udp packet to the device containing the 8-bit digital output and two D/A channel data you want to output and receive a udp packet with that data echoed and the last state of the 8-bit digital input data and two A/D channels. It'll run nicely in a 50-100 mS event loop, on Windows it averages ~25ms from the query packet send to receiving the response packet.

I'm using it to update some old code that used the parallel printer port, seeing how parallel LPT ports are not available on much of the current hardware.

It also has some kind of web server you can use to query with php, but since I don't know php this was not very useful to me, but it might interface with the zoneminder console quite nicely