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# -*- coding: utf-8 -*-
"""ASRL (Serial) simulated session class.
:copyright: 2014-2022 by PyVISA-sim Authors, see AUTHORS for more details.
:license: MIT, see LICENSE for more details.
"""
import time
from typing import Tuple
from pyvisa import constants, rname
from .. import common
from . import session
@session.Session.register(constants.InterfaceType.asrl, "INSTR")
class SerialInstrumentSession(session.MessageBasedSession):
parsed: rname.ASRLInstr
def after_parsing(self) -> None:
self.attrs[constants.ResourceAttribute.interface_number] = int(
self.parsed.board
)
def read(self, count: int) -> Tuple[bytes, constants.StatusCode]:
# TODO: Implement VI_ATTR_SUPPRESS_END_EN
end_in, _ = self.get_attribute(constants.ResourceAttribute.asrl_end_in)
end_char, _ = self.get_attribute(constants.ResourceAttribute.termchar)
end_char = common.int_to_byte(end_char)
enabled, _ = self.get_attribute(constants.ResourceAttribute.termchar_enabled)
timeout, _ = self.get_attribute(constants.ResourceAttribute.timeout_value)
timeout /= 1000
last_bit, _ = self.get_attribute(constants.ResourceAttribute.asrl_data_bits)
mask = 1 << (last_bit - 1)
start = time.monotonic()
out = b""
while time.monotonic() - start <= timeout:
last = self.device.read()
if not last:
time.sleep(0.01)
continue
out += last
if end_in == constants.SerialTermination.termination_char:
if out[-1:] == end_char:
return out, constants.StatusCode.success_termination_character_read
elif end_in == constants.SerialTermination.last_bit:
if common.last_int(out) & mask:
return out, constants.StatusCode.success
if enabled and out[-1:] == end_char:
return out, constants.StatusCode.success_termination_character_read
elif end_in == constants.SerialTermination.none:
if out[-1:] == end_char:
return out, constants.StatusCode.success_termination_character_read
else:
raise ValueError("Unknown value for VI_ATTR_ASRL_END_IN")
if len(out) == count:
return out, constants.StatusCode.success_max_count_read
else:
return out, constants.StatusCode.error_timeout
def write(self, data: bytes) -> Tuple[int, constants.StatusCode]:
send_end, _ = self.get_attribute(constants.ResourceAttribute.send_end_enabled)
asrl_end, _ = self.get_attribute(constants.ResourceAttribute.asrl_end_out)
data_bits, _ = self.get_attribute(constants.ResourceAttribute.asrl_data_bits)
end_char, _ = self.get_attribute(constants.ResourceAttribute.termchar)
end_char = common.int_to_byte(end_char)
len_transferred = len(data)
if asrl_end == constants.SerialTermination.last_bit:
val = b"".join(common.iter_bytes(data, data_bits, send_end))
self.device.write(val)
else:
val = b"".join(common.iter_bytes(data, data_bits, send_end=None))
self.device.write(val)
if asrl_end == constants.SerialTermination.termination_char:
if send_end:
self.device.write(end_char)
len_transferred += 1
elif asrl_end == constants.SerialTermination.termination_break:
if send_end:
# ASRL Break
pass
elif not asrl_end == constants.SerialTermination.none:
raise ValueError("Unknown value for VI_ATTR_ASRL_END_OUT")
return len_transferred, constants.StatusCode.success
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