c2dataviewer 1.6.0

Python based data viewer for next generation of APS control system (C2)

C2DataViewer: EPICS7 pvObject Data Viewer

C2DataViewer is a Python based data viewer for next generation of APS control system (C2). It is developed with pyqtgraph, PyQt, and uses pvaPy as pvAccess Python binding. This is a viewer for pvData structured data objects as transported by pvAccess. Some use cases are a 'scope viewer', and Area Detector images from the AD pva plugin.

Image Application

Image application displays images from an areaDetector pvAccess channel. To start:

c2dv --app image --pv <CHANNELNAME>

Image zoom

Users can zoom into the image by selecting the region of interest. This can be done by drawing the rectangle around the desired area while the mouse button is pressed. To restore the full image Reset zoom should be pressed.

Scope Application

Scope application displays arbitrary information from a pvAccess channel as a time series graph. To start:

c2dv --app scope

Triggering

Scope application supports software triggering via external v3 PV. When trigger mode is configured and trigger occur, selected displayed channels will be updated for the trigger time. Number of samples displayed can be controlled via Buffer (Samples) parameter. Trigger timestamp is always at the middle of the displayed waveform and is marked with the red line.

Types of the records which can be used as the triggers are:

• bi / bo - The trigger event is triggered on transition from 0 -> 1.
• longin / longout - The trigger event is triggered on any value change.
• calc - The trigger event is triggered on any value change.
• event - The trigger event is triggered on any value change.
• ai / ao - The trigger event is triggered when the following condition is true: PV value >= Trigger Threshold.

Follow next steps to configure the trigger:

0. Acquisition must be stopped.
1. Enter Trigger PV (must be available on the network).
2. Enable Trigger Mode.
3. Select Trigger Threshold if the input record is of type ai or ao. For other types this value is ignored.
4. Select desired input channels.
5. Start the acquisition.
6. When the trigger condition is meet, the waveform will draw/update.

Developers Guide

The following information are maintaining and developing C2 Data viewer

Building locally

NOTE : c2dv currently require pyqtgraph version 0.10.0. There is an unresolved issue with the newer version(s): https://git.aps.anl.gov/C2/conda/data-viewer/-/issues/48. Correct version of the pyqtgraph should be installed manually.

To build a conda package:

make

To install build package in a new environment:

conda create -n c2dv.0001 pyqtgraph=0.10.0 local::c2dataviewer -c epics

To run app from new environment:

source activate c2dv.0001
c2dv --app scope

Pip Packaging

To install pip dependencies:

make pip-dependencies

To build a pip package:

# must checkout a particular tag
git checkout 1.5.0
make pip-build

To run the unit tests run:

make pip-test

To upload the package on PyPI:

make pip-upload