async def modify_monitored_item(self, handle: int, new_samp_time, new_queuesize=0, mod_filter_val=-1):
"""
Modify a monitored item.
:param handle: Handle returned when originally subscribing
:param new_samp_time: New wanted sample time
:param new_queuesize: New wanted queuesize, default is 0
:param mod_filter_val: New deadband filter value
:return: Return a Modify Monitored Item Result
"""
# Find the monitored item in the monitored item registry.
item_to_change = next(item for item in self._monitored_items.values() if item.server_handle == handle)
if not item_to_change:
raise ValueError('The monitored item was not found.')
if mod_filter_val is None:
mod_filter = None
elif mod_filter_val < 0:
mod_filter = item_to_change.mfilter
else:
mod_filter = ua.DataChangeFilter()
# send notification when status or value change
mod_filter.Trigger = ua.DataChangeTrigger(1)
mod_filter.DeadbandType = 1
# absolute float value or from 0 to 100 for percentage deadband
mod_filter.DeadbandValue = mod_filter_val
modif_item = ua.MonitoredItemModifyRequest()
modif_item.MonitoredItemId = handle
modif_item.RequestedParameters = self._modify_monitored_item_request(
new_queuesize, new_samp_time, mod_filter, item_to_change.client_handle
)
params = ua.ModifyMonitoredItemsParameters()
params.SubscriptionId = self.subscription_id
params.ItemsToModify.append(modif_item)
results = await self.server.modify_monitored_items(params)
item_to_change.mfilter = results[0].FilterResult
return results
def deadband_monitor(self, var, deadband_val, deadbandtype=1, queuesize=0, attr=ua.AttributeIds.Value):
"""
Method to create a subscription with a Deadband Value.
Default deadband value type is absolute.
Return a handle which can be used to unsubscribe
:param var: Variable to which you want to subscribe
:param deadband_val: Absolute float value
:param deadbandtype: Default value is 1 (absolute), change to 2 for percentage deadband
:param queuesize: Wanted queue size, default is 1
:param attr: Attribute ID
"""
deadband_filter = ua.DataChangeFilter()
# send notification when status or value change
deadband_filter.Trigger = ua.DataChangeTrigger(1)
deadband_filter.DeadbandType = deadbandtype
# absolute float value or from 0 to 100 for percentage deadband
deadband_filter.DeadbandValue = deadband_val
return self._subscribe(var, attr, deadband_filter, queuesize)
