# Do not edit this file; it was automatically generated.
import numpy
import warnings
from nidaqmx import utils
from nidaqmx.errors import DaqResourceWarning
from nidaqmx.system._watchdog_modules.expiration_state import ExpirationState
from nidaqmx.system._watchdog_modules.expiration_states_collection import (
ExpirationStatesCollection)
from nidaqmx.utils import flatten_channel_string
from nidaqmx.constants import (
Edge, TriggerType, WDTTaskAction)
from nidaqmx.types import (
AOExpirationState, COExpirationState, DOExpirationState)
__all__ = ['WatchdogTask']
[docs]
class WatchdogTask:
"""
Represents the watchdog configurations for a DAQmx task.
"""
[docs]
def __init__(self, device_name, task_name='', timeout=10, grpc_options=None):
"""
Creates and configures a task that controls the watchdog timer of a
device. The timer activates when you start the task.
Use the DAQmx Configure Watchdog Expiration States functions to
configure channel expiration states. This class does not program
the watchdog timer on a real-time controller.
Args:
device_name (str): Specifies is the name as configured in MAX of
the device to which this operation applies.
task_name (str): Specifies the name to assign to the task. If you
use this constructor in a loop and specify a name for the task,
you must use the DAQmx Clear Task method within the loop after
you are finished with the task. Otherwise, NI-DAQmx attempts to
create multiple tasks with the same name, which results in an
error.
timeout (float): Specifies the amount of time in seconds until the
watchdog timer expires. A value of -1 means the internal timer
never expires. Set this input to -1 if you use an Expiration
Trigger to expire the watchdog task. If this time elapses, the
device sets the physical channels to the states you specify
with the digital physical channel expiration states input.
grpc_options (Optional[:class:`~nidaqmx.GrpcSessionOptions`]): Specifies
the gRPC session options.
"""
# Initialize the fields that __del__ accesses so it doesn't crash when __init__ raises an exception.
self._handle = None
self._close_on_exit = False
self._saved_name = task_name
self._interpreter = utils._select_interpreter(grpc_options)
self._handle, self._close_on_exit = self._interpreter.create_watchdog_timer_task_ex(device_name, task_name, timeout)
# Saved name is used in self.close() to throw graceful error on
# double closes.
self._saved_name = self.name
self._expiration_states = ExpirationStatesCollection(self._handle, self._interpreter)
def __del__(self):
if self._handle is not None and self._close_on_exit:
warnings.warn(
'Task of name "{}" was not explicitly closed before it was '
'destructed. Resources on the task device may still be '
'reserved.'.format(self._saved_name), DaqResourceWarning)
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
if self._close_on_exit:
self.close()
@property
def expiration_states(self):
"""
:class:`nidaqmx.system._watchdog_modules.expiration_states_collection.ExpirationStatesCollection`: Gets
the collection of expiration states for this watchdog task.
"""
return self._expiration_states
@property
def expir_trig_dig_edge_edge(self):
"""
:class:`nidaqmx.constants.Edge`: Specifies on which edge of a
digital signal to expire the watchdog task.
"""
val = self._interpreter.get_watchdog_attribute_int32(self._handle, "", 0x21a5)
return Edge(val)
@expir_trig_dig_edge_edge.setter
def expir_trig_dig_edge_edge(self, val):
val = val.value
self._interpreter.set_watchdog_attribute_int32(self._handle, "", 0x21a5, val)
@expir_trig_dig_edge_edge.deleter
def expir_trig_dig_edge_edge(self):
self._interpreter.reset_watchdog_attribute(self._handle, "", 0x21a5)
@property
def expir_trig_dig_edge_src(self):
"""
str: Specifies the name of a terminal where a digital signal
exists to use as the source of the Expiration Trigger.
"""
val = self._interpreter.get_watchdog_attribute_string(self._handle, "", 0x21a4)
return val
@expir_trig_dig_edge_src.setter
def expir_trig_dig_edge_src(self, val):
self._interpreter.set_watchdog_attribute_string(self._handle, "", 0x21a4, val)
@expir_trig_dig_edge_src.deleter
def expir_trig_dig_edge_src(self):
self._interpreter.reset_watchdog_attribute(self._handle, "", 0x21a4)
@property
def expir_trig_trig_on_network_conn_loss(self):
"""
bool: Specifies the watchdog timer behavior when the network
connection is lost between the host and the chassis. If set
to true, the watchdog timer expires when the chassis detects
the loss of network connection.
"""
val = self._interpreter.get_watchdog_attribute_bool(self._handle, "", 0x305d)
return val
@expir_trig_trig_on_network_conn_loss.setter
def expir_trig_trig_on_network_conn_loss(self, val):
self._interpreter.set_watchdog_attribute_bool(self._handle, "", 0x305d, val)
@expir_trig_trig_on_network_conn_loss.deleter
def expir_trig_trig_on_network_conn_loss(self):
self._interpreter.reset_watchdog_attribute(self._handle, "", 0x305d)
@property
def expir_trig_trig_type(self):
"""
:class:`nidaqmx.constants.TriggerType`: Specifies the type of
trigger to use to expire a watchdog task.
"""
val = self._interpreter.get_watchdog_attribute_int32(self._handle, "", 0x21a3)
return TriggerType(val)
@expir_trig_trig_type.setter
def expir_trig_trig_type(self, val):
val = val.value
self._interpreter.set_watchdog_attribute_int32(self._handle, "", 0x21a3, val)
@expir_trig_trig_type.deleter
def expir_trig_trig_type(self):
self._interpreter.reset_watchdog_attribute(self._handle, "", 0x21a3)
@property
def expired(self):
"""
bool: Indicates if the watchdog timer expired. You can read this
property only while the task is running.
"""
val = self._interpreter.get_watchdog_attribute_bool(self._handle, "", 0x21a8)
return val
@property
def timeout(self):
"""
float: Specifies in seconds the amount of time until the
watchdog timer expires. A value of -1 means the internal
timer never expires. Set this input to -1 if you use an
Expiration Trigger to expire the watchdog task.
"""
val = self._interpreter.get_watchdog_attribute_double(self._handle, "", 0x21a9)
return val
@timeout.setter
def timeout(self, val):
self._interpreter.set_watchdog_attribute_double(self._handle, "", 0x21a9, val)
@timeout.deleter
def timeout(self):
self._interpreter.reset_watchdog_attribute(self._handle, "", 0x21a9)
@property
def name(self):
"""
str: Indicates the name of the task.
"""
val = self._interpreter.get_task_attribute_string(self._handle, 0x1276)
return val
def _control_watchdog_task(self, action):
"""
Controls the watchdog timer task according to the action you
specify. This function does not program the watchdog timer on a
real-time controller. Use the Real-Time Watchdog VIs to program
the watchdog timer on a real-time controller.
Args:
action (nidaqmx.constants.WDTTaskAction): Specifies how to
control the watchdog timer task.
"""
self._interpreter.control_watchdog_task(self._handle, action.value)
[docs]
def cfg_watchdog_ao_expir_states(self, expiration_states):
"""
Configures the expiration states for an analog watchdog timer task.
Args:
expiration_states
(List[nidaqmx.system.watchdog.AOExpirationState]):
Contains the states to which to set analog physical channels
when the watchdog timer expires. Each element of the list
contains an analog physical channel name, the corresponding
expiration state, and the output type for that analog
physical channel. The units of "expiration state" must be
specified in volts for an analog output voltage expiration
state, or amps for an analog output current expiration state.
physical_channel (str): Specifies the analog output channel to
modify. You cannot modify dedicated analog input lines.
expiration_state (float): Specifies the value to set the
channel to upon expiration.
output_type (nidaqmx.constants.WatchdogAOExpirState):
Specifies the output type of the physical channel.
Returns:
List[nidaqmx.system._watchdog_modules.expiration_state.ExpirationState]:
Indicates the list of objects representing the configured
expiration states.
"""
channel_names = flatten_channel_string(
[e.physical_channel for e in expiration_states])
expir_state = numpy.array(
[e.expiration_state for e in expiration_states], dtype=numpy.float64)
output_type = numpy.array(
[e.output_type.value for e in expiration_states], dtype=numpy.int32)
self._interpreter.cfg_watchdog_ao_expir_states(self._handle, channel_names, expir_state, output_type)
return [ExpirationState(self._handle, e.physical_channel, self._interpreter)
for e in expiration_states]
[docs]
def cfg_watchdog_co_expir_states(self, expiration_states):
"""
Configures the expiration states for a counter watchdog timer task.
Args:
expiration_states
(List[nidaqmx.system.watchdog.COExpirationState]):
Contains the states to which to set counter physical channels
when the watchdog timer expires. Each element of the list
contains a counter physical channel name and the corresponding
state for that counter physical channel.
physical_channel (str): Specifies the counter output channel to
modify. You cannot modify dedicated counter input lines.
expiration_state (nidaqmx.constants.WatchdogCOExpirState):
Specifies the value to set the channel to upon expiration.
Returns:
List[nidaqmx.system._watchdog_modules.expiration_state.ExpirationState]:
Indicates the list of objects representing the configured
expiration states.
"""
channel_names = flatten_channel_string(
[e.physical_channel for e in expiration_states])
expir_state = numpy.array(
[e.expiration_state.value for e in expiration_states], dtype=numpy.int32)
self._interpreter.cfg_watchdog_co_expir_states(self._handle, channel_names, expir_state)
return [ExpirationState(self._handle, e.physical_channel, self._interpreter)
for e in expiration_states]
[docs]
def cfg_watchdog_do_expir_states(self, expiration_states):
"""
Configures the expiration states for a digital watchdog timer task.
Args:
expiration_states
(List[nidaqmx.system.watchdog.DOExpirationState]):
Contains the states to which to set digital physical channels
when the watchdog timer expires. Each element of the list
contains a digital physical channel name and the corresponding
state for that digital physical channel.
physical_channel (str): Specifies the digital output channel to
modify. You cannot modify dedicated digital input lines.
expiration_state (nidaqmx.constants.Level): Specifies the
value to set the channel to upon expiration.
Returns:
List[nidaqmx.system._watchdog_modules.expiration_state.ExpirationState]:
Indicates the list of objects representing the configured
expiration states.
"""
channel_names = flatten_channel_string(
[e.physical_channel for e in expiration_states])
expir_state = numpy.array(
[e.expiration_state.value for e in expiration_states], dtype=numpy.int32)
self._interpreter.cfg_watchdog_do_expir_states(self._handle, channel_names, expir_state)
return [ExpirationState(self._handle, e.physical_channel, self._interpreter)
for e in expiration_states]
[docs]
def clear_expiration(self):
"""
Unlock a device whose watchdog timer expired.
This function does not program the watchdog timer on a real-time
controller. Use the Real-Time Watchdog VIs to program the watchdog
timer on a real-time controller.
"""
self._control_watchdog_task(WDTTaskAction.CLEAR_EXPIRATION)
[docs]
def close(self):
"""
Clears the task.
Before clearing, this method aborts the task, if necessary,
and releases any resources the task reserved. You cannot use a task
after you clear it unless you recreate the task.
If you create a DAQmx Task object within a loop, use this method
within the loop after you are finished with the task to avoid
allocating unnecessary memory.
"""
if self._handle is None:
warnings.warn(
'Attempted to close NI-DAQmx task of name "{}" but task was '
'already closed.'.format(self._saved_name), DaqResourceWarning)
return
self._interpreter.clear_task(self._handle)
self._handle = None
[docs]
def control(self, action):
"""
Alters the state of a task according to the action you specify.
Args:
action (nidaqmx.constants.TaskMode): Specifies how to alter
the task state.
"""
self._interpreter.task_control(self._handle, action.value)
[docs]
def reset_timer(self):
"""
Reset the internal timer. You must continually reset the internal
timer to prevent it from timing out and locking the device.
This function does not program the watchdog timer on a real-time
controller. Use the Real-Time Watchdog VIs to program the watchdog
timer on a real-time controller.
"""
self._control_watchdog_task(WDTTaskAction.RESET_TIMER)
[docs]
def start(self):
"""
Transitions the task to the running state to begin the measurement
or generation. Using this method is required for some applications and
is optional for others.
"""
self._interpreter.start_task(self._handle)
[docs]
def stop(self):
"""
Stops the task and returns it to the state the task was in before the
DAQmx Start Task method ran.
"""
self._interpreter.stop_task(self._handle)