import logging
import asyncio
logger = logging.getLogger(__name__)
[docs]class VoltageProtocol:
"""Protocol for the PTB multi-channel voltage source"""
def do(self, cmd):
logger.debug("do %s", cmd)
self._writeline(cmd)
async def ask(self, cmd):
self.do(cmd)
ret = await self._readline()
logger.debug("ret %s", ret)
return ret
async def read(self, n):
ret = await self._read(n)
return ret.decode()
[docs] async def version(self):
"""Return the hardware/firmware version.
Returns:
str: Version string.
"""
return (await self.ask("get version")).strip()
def _writeline(self, cmd):
raise NotImplemented
async def _readline(self):
raise NotImplemented
async def ping(self):
try:
await self.version()
except asyncio.CancelledError:
raise
except:
logger.warning("ping failed", exc_info=True)
return False
return True
async def _cmd(self, action, name, args=""):
assert action in ("get", "set")
cmd = "{} {}".format(action, name)
ret = await self.ask(cmd + args)
assert ret.startswith(cmd)
return ret[len(cmd):].strip()
[docs] async def get_temperature(self):
"""Get temperature data for controller and amplifier
boards.
Returns:
list(float): Raw ADC values for the NTCs
"""
ret = await self._cmd("get", "temp")
return [int(_) for _ in ret.split()]
[docs] def ldac(self):
"""Pulse LDAC to all DACs to load values into active registers."""
return self._cmd("set", "ldac")
[docs] def factory(self):
"""Reset gains and offsets to default values"""
return self._cmd("set", "factory")
async def _values(self, action, name, values, channels=None, conv=float):
if channels is None:
channels = list(range(1, len(values) + 1))
args = " ".join("{} {}".format(channel, value)
for channel, value in zip(channels, values))
ret = await self._cmd(action, name,
" {} {}".format(len(values), args))
v = ret.split()
assert len(v) % 2 == 1
n = int(v.pop(0))
assert len(v) == 2*n
channels_ret = [int(_) for _ in v[::2]]
values_ret = [conv(_) for _ in v[1::2]]
assert channels_ret == channels
# assert values_ret == values
return values_ret, channels_ret
[docs] def set_voltage(self, values, channels=None):
"""Set output voltages. Voltages become active only after
:meth:`ldac`.
Args:
values (list(float)): Voltages, one for each target channel.
channels (list(int)): Target channels. Defaults to 1...len(values)
Returns:
list(float): Actual values returned by the device.
"""
return self._values("set", "volt", values, channels, float)
[docs] def set_gain(self, values, channels=None):
"""Set channel gains. Channel gains are processed within the
microcontroller and become active on :meth:`set_volt` and a subsequent
:meth:`ldac`.
Gains are given in `2**16/full_scale` where
`full_scale = u_max - u_min`.
Args:
values (list(float)): Gains, one for each target channel.
channels (list(int)): Target channels. Defaults to 1...len(values)
Returns:
list(float): Actual values returned by the device.
"""
return self._values("set", "gain", values, channels, float)
[docs] def set_offset(self, values, channels=None):
"""Set channel offsets. Channel gains are processed within the
microcontroller and become active on :meth:`set_volt` and a subsequent
:meth:`ldac`.
Offsets are given in DAC LSBs (integers).
Args:
values (list(int)): Offsets, one for each target channel.
channels (list(int)): Target channels. Defaults to 1...len(values)
Returns:
list(int): Actual values returned by the device.
"""
return self._values("set", "offset", values, channels, int)
[docs] def set_data(self, values, channels=None):
"""Set raw channel output values. Values are given in DAC LSBs
(integers). Data becomes active only after :meth:`ldac`.
Args:
values (list(int)): DAC values, one for each target channel.
channels (list(int)): Target channels. Defaults to 1...len(values)
Returns:
list(int): Actual values returned by the device.
"""
return self._values("set", "data", values, channels, int)
[docs] def get_data(self, channels=None):
"""Get raw channel output values. Values are given in DAC LSBs
(integers).
Args:
channels (list(int)): Target channels. Defaults to 1...8
Returns:
list(int)): DAC values, one for each target channel.
"""
if channels is None:
channels = list(range(1, 8 + 1))
values = [0 for i in range(len(channels))]
return self._values("get", "data", values, channels, int)