Hamilton command read_timeout not adjustable

[nedru004]

I am trying to run a protein purification that slowly pipettes a solution over a resin inside a tip. When I set the volume to 400 and the flowrate to 0.4ul/s it times out after 300 seconds. I changed the backend timeout to 1200 to account for the 1000 seconds it would take, but it continues to timeout at 300.

from pylabrobot.liquid_handling import LiquidHandler
from pylabrobot.liquid_handling.backends import STARBackend
from pylabrobot.resources.hamilton import STARDeck

lh = LiquidHandler(backend=STARBackend(read_timeout=1200), deck=STARDeck(core_grippers="1000uL-5mL-on-waste"))
await lh.setup(skip_iswap=True)

await lh.pick_up_tips96(lh.deck.get_resource("imac_tips"))
await lh.aspirate96(lh.deck.get_resource(plate_loc), volume=400, flow_rate=0.4)

I found that the command should default to lh.backend.read_timeout. Is there an upper limit to read_timeout with the usb package?

pylabrobot/pylabrobot/liquid_handling/backends/hamilton/base.py

Lines 281 to 283 in e5955b0

	# Attempt to read packets until timeout, or when we identify the right id.
	if read_timeout is None:
	read_timeout = self.read_timeout

[rickwierenga]

i am not able to reproduce this...

with default values, it times out in 30 seconds (not 300) since that is the backend default

however when i set STARBackend(read_timeout=60) it correctly times out after one minute

are you on v0.2? or main?

[nedru004]

I am on main. Are you able to get it to timeout past 300 sec? I am on a windows machine. What system are you on? Perhaps there is a limit with libusbK? I will send you the Error when I am in the lab tomorrow. Thanks for looking into this. My alternative is to aspirate multiple times less than 300 sec.