"""
Establishes a connection to the Switched Integrator Amplifier
(SIA3 board) that is designed by the `Czech Metrology Institute`_.
.. _Czech Metrology Institute: https://www.cmi.cz/?language=en
"""
from __future__ import annotations
from enum import IntEnum
from msl.equipment.connection_serial import ConnectionSerial
from msl.equipment.exceptions import CMIError
from msl.equipment.resources import register
[docs]
class IntegrationTime(IntEnum):
"""The amount of time to integrate the photo-diode signal."""
TIME_50u = 5
TIME_100u = 6
TIME_1m = 7
TIME_10m = 8
TIME_20m = 9
TIME_100m = 10
TIME_200m = 11
TIME_500m = 12
TIME_1 = 13
TIME_2 = 14
[docs]
@register(manufacturer=r'C.*M.*I', model=r'SIA3')
class SIA3(ConnectionSerial):
GAIN = IntegrationTime #: The gain (i.e., the integration time)
def __init__(self, record):
"""
Establishes a connection to the Switched Integrator Amplifier
(SIA3 board) that is designed by the `Czech Metrology Institute`_.
Do not instantiate this class directly. Use the :meth:`~.EquipmentRecord.connect`
method to connect to the equipment.
.. _Czech Metrology Institute: https://www.cmi.cz/?language=en
Parameters
----------
record : :class:`~.EquipmentRecord`
A record from an :ref:`equipment-database`.
"""
if not record.connection.properties:
# then use the default connection properties
record.connection.properties = {
'baud_rate': 14400,
'termination': None,
'timeout': 10.0,
}
super(SIA3, self).__init__(record)
self.set_exception_class(CMIError)
[docs]
def set_integration_time(self, time):
"""Set the integration time (i.e., the gain).
Parameters
----------
time : :class:`.IntegrationTime`
The integration time as a :class:`.IntegrationTime` enum value or member name,
e.g., ``sia.set_integration_time('10m')``, ``sia.set_integration_time(sia.GAIN.TIME_10m)``
and ``sia.set_integration_time(8)`` are all equivalent statements.
"""
self._send_byte(7)
self._send_byte(self.convert_to_enum(time, IntegrationTime, prefix='TIME_'))
[docs]
def set_ps(self, ps):
"""Set the timer pre-scale value.
The timer pre-scale value divides the microprocessor internal frequency
by something similar to 2^PS. Therefore, to reach a 2-second integration time
the `ps` value must be set to the maximum value of 7.
Parameters
----------
ps : :class:`int`
The timer pre-scale value. Must be in the range [0, 7].
Raises
------
ValueError
If the value of `ps` is invalid.
"""
_ps = int(ps)
if _ps < 0 or _ps > 7:
raise ValueError('Invalid PS value of {}. Must be 0 <= PS <= 7.'.format(ps))
self._send_byte(1)
self._send_byte(4)
self._send_byte(_ps)
self._send_byte(_ps)
def _send_byte(self, byte):
self.write(chr(byte))