How to acquire data with specMACS

The specMACS data acquisition system is built on ideas of the actor model and tries to be highly configureable and modular. This modularity is immediately visible to the user, as many separate processes have to be started to offer a running acquisition system as a combination of them.

Background setup

To allow all of the components to talk to each other, two main parts are needed:

• A running rocbroker, which is a server to wich all components register and which is responsible for relaying messages between them.
• A capture config, which states the address of the rocbroker and some auxiliary configuration options.

As a starting point, the following simple configuration file can be stored under ~/.macs/capture.json:

{
    "broker": "<IP or hostname of broker>",
    "cameras":[
        {
            "name": "vnir",
            "type": "imaq",
            "source": "RSCUBE_VNIR::img0"
        },
        {
            "name": "swir",
            "type": "imaq",
            "source": "RSCUBE_SWIR::img0"
        }
    ],
    "storageLocations": ["K:/"]
}

After adding the IP address or hostname of the computer running the rocbroker, this will configure a capturing system with two cameras, and store data under K:/.

The next step is to start the rocbroker by the following command:

python -m runmacs.roc.rocbroker

Getting data from the cameras

Image data is received from the cameras by the camserver, which is a C++ program. It can be found under cpp/camserver[.exe] after a simple make in the cpp directory. Start it simply by issuing:

camserver

From inside the cpp directory (or ./camserver for simulation under Linux/OSX).

The camserver will read the configuration and start a data acquisition thread for each listed camera. It will further connect to the rocbroker waiting for additional commands.

User interface

Up to now, no visble feedback is available to the user and no data is actually stored on disk. Therefore, at least one user interface should be started. Try one (or both) of:

python spec_gui.py
python spec_gui_simple.py

In the root directory of the source tree.

note:For the simple gui, a short PDF-Manual is available here.

Changing camera settings

The camserver is only responsible for getting and storing image data. Changing camera settings is subject to another program, one for each camera. As most other actors, these can be found at runmacs/roc/servers. So start the following two actors:

python -m runmacs.roc.servers.vnir
python -m runmacs.roc.servers.swir

As soon as they are running, it should be possible to read an set the cameras framerate and integration time using spec_gui.py. spec_gui_simple.py additionally requires the autoexposure actors to regulate the integration time. They can be started using:

python -m runmacs.roc.servers.vnir_autoexp
python -m runmacs.roc.servers.swir_autoexp

Logging

Log messages are automatically distributed using the rocbroker, you can already see them in one of the user interfaces. If you want to store them to a file, use logdump.

Supervisor

To keep all of the needed programs running, it is advisable to use a supervisor like Ramona or supervisord.