Python Applications for beamline control/analysis

Tim Mooney

ca_util.py – thin layer above CaChannel

plot.py – display 1D of a scan

readMDA.py – read MDA file format

detView.py – display images from 2D scan

ca_util.py

• Automatic dictionary:

PV name : CaChannel object

• caget(PVname)

• caput(PVname, value)

• caputw(PVname, value)

• camonitor(PVname, python function, user args)

• caunmonitor(PVname)

plot.py

readMDA.pyfrom readMDA import *

d = readMDA(filename, max_dimension, verbose, help)

returns a list:

d[0] – dictionary of scan-environment variables (mostly PV names)

e.g., d[0][‘2idd:mca1.R2LO’] = (‘ROI_2_LEFT:’,’’,[342])

d[n>0] one dimension of the scan, with the following fields:

time - date & time at which scan was started

scan_name - name of scan record that acquired this dimension

curr_pt - number of data points actually acquired

npts - number of data points requested

nd - number of detectors for this scan dimension

d[] - list of detector-data structures

np - number of positioners for this scan dimension

p[] - list of positioner-data structures

nt - number of detector triggers for this scan dimension

t[] - list of trigger-info structures

readMDA.pyeach detector-data structure (e.g., d[1].d[0]) has the following fields:

desc - description of this detector

data - data list

unit - engineering units associated with this detector

fieldName - scan-record field (e.g., 'D01')

each positioner-data structure (e.g., d[1].p[0]) has the following fields:

desc - description of this positioner

data - data list

step_mode - scan mode (e.g., Linear, Table, On-The-Fly)

unit - engineering units associated with this positioner

fieldName - scan-record field (e.g., 'P1')

name - name of EPICS PV (e.g., 'xxx:m1.VAL')

readback_desc - description of this positioner

readback_unit - engineering units associated with this positioner

readback_name - name of EPICS PV (e.g., 'xxx:m1.VAL')

detView.pyRequires numeric.py

from readMDA import *

from detView import *

d=readMDA(“2idd_0004.mda”)

detView(d[2].d[0:15],scale=(2,2),columns=5)