Retrieval

EPICS Archiver Appliance data retrieval is based on REST API.

Creating the ArchiverReader Instance

An ArchiverReader instance is created by specifing the Archiver Retrieval service address and time zone:

from arvpyf.ar import ArchiverReader

ar_url = 'http://xf23id-ca.cs.nsls2.local:17668'
ar_tz = 'US/Eastern'

config = {'url': ar_url, 'timezone': ar_tz}

arvReader = ArchiverReader(config)

Data Retrieval

The data retrieval interface is encapsulated in the get() method using three arguments: EPICS PV name and the start/end times. As a result, the method returns a pandas.DataFrame with the time and data columns.

pv = 'XF:23ID-ID{BPM}Val:PosXS-I'
since = '2016-10-06 17:55:35'
until = '2016-10-06 17:54:35'

df = arvReader.get(pv, since, until)