Setting scan to 0 through setParamInfo

[hinxx]

I would like to switch between passive and periodic scan.
If the PV has initial scan set to non zero for createPV, is it allowed to set it to 0 during the runtime with self.setParamInfo('det1:trig', {'scan': 0})?

If I do that the PV updates, seen by the camonitor, are flooding my console with PV value changing rapidly.

[xiaoqiangwang]

The scan thread is only created on startup,

pcaspy/pcaspy/driver.py

Lines 513 to 517 in f2f59c0

	# scan thread
	if self.info.scan > 0:
	self.tid = threading.Thread(target=self.scan)
	self.tid.daemon = True
	self.tid.start()

So switch from passive to periodic is not possible.

The scan value is directly used to the delay function,

pcaspy/pcaspy/driver.py

Line 532 in f2f59c0

time.sleep(self.info.scan)

There is currently no way to stop it.