UTC Alarm Receiver

utcar acts as a central station to a ATS alarm system and has been tested using an ATS2000IP system. It might work with other variants as well. The communication between the alarm system and utcar is using OH+XSIA protocol. I'm not an expert, but I assume that any system that uses this protocol should be compatible (naive? me?).

My use case:

leverage the alarms systems events (e.g. motion, window sensors) as input to home automation

Configure your alarm system

Your alarm is typically configured to send messages to a central station in case of alarm, fire, etc... The link is checked for health by sending periodic heartbeat messages. In my case, these heartbeat messages are sent every minute.

For utcar to work, we'll configure it in the alarm system as a new central station. Since we don't want to interrupt messages going to the first central station (the one calling the police in case of an alarm), we need to go through a few steps to make this work. Let's assume we want to get notified when a motion sensor is triggered.

Create a new area that we'll use with utcar. This allows us to keep automation for utcar separate from the actual alarms going to the formal central station. Let's pick area 4.
Configure a filter that follows the motion detector
Configure an output to follow the filter
Configure a new zone, and configure the output as its virtual zone. Configure it in area 4.
Configure a new central station (IP based), configure it with the host IP address of the machine where you'll be running utcar. Also pick a port number, by default utcar runs on port 12300. Associate this central station with area 4.

Running utcar

Usage of ./utcar:
  --port=12300: Listen port number (default: 12300)
  --addr="": Target addr (e.g. http://openhab.local:8080)
  --pwd="": Target password
  --user="": Target username

Example:

./utcar -port=10000 --addr=https://localhost:8443 --user=yourname --pwd=yourpass
2014/09/25 06:40:32 Listing on port 10000...
2014/09/25 06:40:32 Pushing to localhost:8443

Example with environment variables:

UTCAR_PORT=12000 ./utcar
2020/04/25 12:37:38 Listing on port 12000...

utcar listens by default on port number 12300, can be set on command line (--port)

The alarm must be configured to send OH+XSIA messages. In that case it will send two types of messages: heartbeats and (X)SIA messages. The heartbeats look like this:

SR0001L0001    001465XX    [ID5B9490D8]

At this point, heartbeats are logged but ignored further.

The (X)SIA messages are more interesting, the look like this:

01010053"SIA-DCS"0007R0073L0011[#001365|NUA021*'detector hall'NM]7C9677F21948CC12|#001365

This is a message to indicate activation (UA) of a motion sensor in zone 21 (detector in hall). If no --addr is provided, we only log this message.

if a --addr parameter is provided, then utcar will POST a message to an HTTP endpoint. Right now, this is customized for Openhab - might need to generalize this later.

URL for the POST: <addr>/rest/items/al_{item}/state, where item is the zone received from the alarm.

For the example above, an HTTP POST with body ON is sent to:

<addr>/rest/items/al_021/state

You can provide --user and --pwd to provide basic authentication.

If an (X)SIA message of UR is received, an OFF message is sent. Support for more messages types might be added later.

Running in a container

You can also run utcar in a container:

docker run -p 10000:10000 tdeckers/utcar --port=10000 --addr=https://localhost:8443

Or alternatively:

docker run -p 12300:12300 -e UTCAR_ADDR=https://localhost:8443 tdeckers/utcar

Building

To cross-compile for different platforms, set up your cross compilers for the platforms you need.

cd $GOROOT/src
# Windows 64-bit
GOOS=windows GOARCH=amd64 ./make.bash --no-clean
# Raspberry Pi
GOOS=linux GOARCH=arm ./make.bash --no-clean

Then to compile your app:

cd $YOUR_APP
GOOS=windows GOARCH=amd64 go build

Note: 3 versions are provided: for Windows 64, arm32 (for raspberry pi) and for linux64. See releases.

Building a container

(thanks: https://rollout.io/blog/building-minimal-docker-containers-for-go-applications/)

First build a statically linked executable:

CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build -a -installsuffix cgo
cp /etc/ssl/certs/ca-certificates.crt .
docker build -t utcar .

Then run the container:

docker run --addr=http://localhost:8080

docker run -e UTCAR_ADDR=http://localhost:8080 utcar

Credits: Thanks to Dirk @ OP for his help on the ATS configuration.