Examples¶

Initialisation¶

Import ‘pytac’ and initialise the VMX ring mode:

>>> import pytac.load_csv
>>> lattice = pytac.load_csv.load('VMX')

The lattice object is used for interacting with elements of the accelerator.

Print BPM pvs along with s position¶

Get elements representing BPMs:
```
>>> bpms = lattice.get_elements('BPM')
```

Print the device names and s position of each BPM:

>>> for bpm in bpms:
>>>    print('BPM {} at position {}'.format(bpm.get_device('x').name, lattice.get_s(bpm)))
BPM SR01C-DI-EBPM-01 at position 4.38
BPM SR01C-DI-EBPM-02 at position 8.8065
BPM SR01C-DI-EBPM-03 at position 11.374
BPM SR01C-DI-EBPM-04 at position 12.559
BPM SR01C-DI-EBPM-05 at position 14.9425
...

Get PV names and positions for BPMs directly from the lattice object:

>>> lattice.get_pv_names('BPM', 'x', pytac.RB)
['SR01C-DI-EBPM-01:SA:X',
'SR01C-DI-EBPM-02:SA:X',
'SR01C-DI-EBPM-03:SA:X'
...
>>> lattice.get_pv_names('BPM', 'y', pytac.RB)
['SR01C-DI-EBPM-01:SA:Y',
'SR01C-DI-EBPM-02:SA:Y',
'SR01C-DI-EBPM-03:SA:Y',
...
>>> lattice.get_family_s('BPM')
[4.38,
 8.806500000000002,
 11.374000000000002,
 ...

Get the pv value from the quad elements¶

Get the Quad elements and print their readback values on the b1 field:

>>> quads = lattice.get_elements('QUAD')
>>> for quad in quads:
>>>    print(quad.get_pv_value('b1', pytac.RB))
71.3240509033
129.351394653
98.2537231445
...

Print the quad pv values on the b1 field using the lattice. This is more efficient since it uses only one request to the control system:
```
>>> lattice.get_pv_values('QUAD', 'b1', pytac.RB)
[71.32496643066406,
 129.35191345214844,
 98.25287628173828,
...
```