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fix(ddg): Fix timing and delays on ddg.

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This commit is contained in:
appel_c
2026-03-13 13:56:22 +01:00
parent 4b04e7a35d
commit 541813a02e
2 changed files with 51 additions and 6 deletions
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39
csaxs_bec/devices/epics/delay_generator_csaxs/ddg_1.py
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@@ -104,7 +104,7 @@ DEFAULT_REFERENCES: list[tuple[LiteralChannels, CHANNELREFERENCE]] = [
("B", CHANNELREFERENCE.A),
("C", CHANNELREFERENCE.T0), # T0
("D", CHANNELREFERENCE.C),
("E", CHANNELREFERENCE.D), # D One extra pulse once shutter closes for MCS
("E", CHANNELREFERENCE.B), # B One extra pulse once shutter closes for MCS
("F", CHANNELREFERENCE.E), # E + 1mu s
("G", CHANNELREFERENCE.T0),
("H", CHANNELREFERENCE.G),
@@ -213,8 +213,24 @@ class DDG1(PSIDeviceBase, DelayGeneratorCSAXS):
# NOTE Burst delay should be set to 0, don't remove as this will not be checked
# Also set the burst count to 1 to only have a single pulse for DDG1.
# As the IOC may be out of sync with the HW, we make sure that we set the default parameters
# in the IOC to the expected values. In the past, we've experienced that IOC and HW can go out
# of sync.
self.burst_delay.put(1)
time.sleep(0.02) # Give HW time to process
self.burst_delay.put(0)
time.sleep(0.02)
self.burst_count.put(2)
time.sleep(0.02)
self.burst_count.put(1)
time.sleep(0.02)
self.burst_mode.put(0)
time.sleep(0.02)
self.burst_mode.put(1)
time.sleep(0.02)
def keep_shutter_open_during_scan(self, open: True) -> None:
"""
@@ -291,17 +307,28 @@ class DDG1(PSIDeviceBase, DelayGeneratorCSAXS):
# Burst Period DDG1
# Set burst_period to shutter width
# c/t0 + self._shutter_to_open_delay + exp_time * burst_count
# SHUTTER WIDTH timing consists of the delay for the shutter to open
# + the exposure time * frames per trigger
shutter_width = (
self._shutter_to_open_delay + exp_time * frames_per_trigger
) # Shutter starts closing at end of exposure
)
# TOTAL EXPOSURE accounts for the shutter to open AND close. In addition, we add
# a short additional delay of 3e-6 to allow for the extra trigger through 'ef'
# (delay of 1e-6, width of 1e-6)
total_exposure_time = (
2*self._shutter_to_open_delay + exp_time*frames_per_trigger + 3e-6
)
if self.burst_period.get() != shutter_width:
self.burst_period.put(shutter_width)
# The burst_period has to be slightly longer
self.burst_period.put(total_exposure_time)
# Trigger DDG2
# a = t0 + 2ms, b = a + 1us
# a has reference to t0, b has reference to a
# Add delay of self._shutter_to_open_delay to allow shutter to open
self.set_delay_pairs(channel="ab", delay=self._shutter_to_open_delay, width=1e-6)
# AB is delayed by the shutter opening time, and the falling edge indicates the shutter has
# fully closed, it has to be considered as the blocking signal for the next acquisition to start.
# PS: + 3e-6
self.set_delay_pairs(channel="ab", delay=self._shutter_to_open_delay, width=shutter_width)
# Trigger shutter
# d = c/t0 + self._shutter_to_open_delay + exp_time * burst_count + 1ms
@@ -321,7 +348,7 @@ class DDG1(PSIDeviceBase, DelayGeneratorCSAXS):
if self.scan_info.msg.scan_type == "fly":
self.set_delay_pairs(channel="ef", delay=0, width=0)
else:
self.set_delay_pairs(channel="ef", delay=0, width=1e-6)
self.set_delay_pairs(channel="ef", delay=1e-6, width=1e-6)
# NOTE Add additional sleep to make sure that the IOC and DDG HW process the values properly
# This value has been choosen empirically after testing with the HW. It's

18
csaxs_bec/devices/epics/delay_generator_csaxs/ddg_2.py
View File

@@ -138,6 +138,24 @@ class DDG2(PSIDeviceBase, DelayGeneratorCSAXS):
# Set burst config
self.burst_config.put(BURSTCONFIG.FIRST_CYCLE.value)
# TODO As the IOC may be out of sync with the HW, we make sure that we set the default parameters
# in the IOC to the expected values. In the past, we've experienced that IOC and HW can go out
# of sync.
self.burst_delay.put(1)
time.sleep(0.02) # Give HW time to process
self.burst_delay.put(0)
time.sleep(0.02)
self.burst_count.put(2)
time.sleep(0.02)
self.burst_count.put(1)
time.sleep(0.02)
self.burst_mode.put(0)
time.sleep(0.02)
self.burst_mode.put(1)
time.sleep(0.02)
def on_stage(self) -> DeviceStatus | StatusBase | None:
"""