def __init__(self, manager, resID, **kwargs):
assert (isinstance(manager, labtronyx.InstrumentManager))
super(r_Serial, self).__init__(manager, resID, **kwargs)
# Ensure resource doesn't already exist
if len(manager.plugin_manager.searchPluginInstances(pluginType='resource', interfaceName='Serial',
resID=resID)) > 0:
raise labtronyx.InterfaceError("Resource already exists")
try:
self.instrument = serial.Serial(port=resID, timeout=0)
self.logger.debug("Created Serial resource: %s", resID)
# Serial port is immediately opened on object creation
self.close()
except (serial.SerialException, OSError) as e:
if os.name == 'nt':
# Windows implementation of PySerial does not set errno correctly
import ctypes
e.errno = ctypes.WinError().errno
if e.errno in [errno.ENOENT, errno.EACCES, errno.EBUSY]:
raise labtronyx.ResourceUnavailable('Serial resource error: %s' % resID)
else:
raise labtronyx.InterfaceError('Serial interface error [%i]: %s' % (e.errno, e.message))
def __init__(self, manager, resID, **kwargs):
assert (isinstance(manager, labtronyx.InstrumentManager))
super(r_VISA, self).__init__(manager, resID, **kwargs)
# Ensure dependency was resolved correctly
if not isinstance(self.interface, i_VISA):
raise labtronyx.InterfaceError("VISA Interface is not enabled")
# Ensure resource doesn't already exist
if len(
manager.plugin_manager.searchPluginInstances(
pluginType='resource', interfaceName='VISA',
resID=resID)) > 0:
raise labtronyx.InterfaceError("Resource already exists")
try:
self.instrument = self.interface.resource_manager.open_resource(
resID)
self.logger.debug("Created VISA resource: %s", resID)
# Instance variables
self._identity = []
self._conf = { # Default configuration
'read_termination': '\r',
'write_termination': '\r\n',
'timeout': 2000
}
self._resourceType = self.RES_TYPES.get(
self.instrument.interface_type, 'VISA')
# Instrument is created in the open state, but we do not want to lock the VISA instrument
self.close()
# Set a flag to initialize the resource when it is used
self.ready = False
# except AttributeError:
# raise labtronyx.ResourceUnavailable('Invalid VISA Resource Identifier: %s' % resID)
except visa.VisaIOError as e:
if e.abbreviation in [
"VI_ERROR_RSRC_BUSY", "VI_ERROR_RSRC_NFOUND",
"VI_ERROR_TMO", "VI_ERROR_INV_RSRC_NAME"
]: # Returned by TekVISA
raise labtronyx.ResourceUnavailable('VISA Resource Error: %s' %
e.abbreviation)
else:
raise labtronyx.InterfaceError('VISA Interface Error: %s' %
e.abbreviation)
def read_raw(self, size=None):
"""
Read Binary-encoded data from the instrument.
No termination characters are stripped.
:param size: Number of bytes to read
:type size: int
:returns: bytes
:raises: ResourceNotOpen
"""
try:
ret = bytes()
if size is None:
size = self.instrument.inWaiting()
ret += self.instrument.read(size)
if len(ret) != len(size):
raise labtronyx.InterfaceTimeout("Timeout before requested bytes could be read")
return ret
except SerialException as e:
if e == serial.portNotOpenError:
raise labtronyx.ResourceNotOpen()
else:
raise labtronyx.InterfaceError(e.strerror)
def read(self, termination=None):
"""
Read string data from the instrument.
Reading stops when the device stops sending, or the termination
characters sequence was detected.
All line-ending characters are stripped from the end of the string.
:raises: ResourceNotOpen
"""
try:
ret = ''
if termination is None:
bytes_waiting = self.instrument.inWaiting()
ret += self.instrument.read(bytes_waiting)
else:
ret += self.instrument.read(1)
while ret[-1] != self.termination[-1] or self.instrument.inWaiting() == 0:
ret += self.instrument.read(1)
ret = ret[:-len(self.termination)]
return ret
except SerialException as e:
if e == serial.portNotOpenError:
raise labtronyx.ResourceNotOpen()
else:
raise labtronyx.InterfaceError(e.strerror)
def write(self, data):
"""
Send ASCII-encoded data to the instrument. Includes termination character.
Raises exception if the resource is not open
:param data: Data to send
:type data: str
:raises: ResourceNotOpen
:raises: InterfaceTimeout
:raises: InterfaceError
"""
try:
self.logger.debug("Serial Write: %s", data)
self.instrument.write(data + self.termination)
except SerialException as e:
if e == serial.portNotOpenError:
raise labtronyx.ResourceNotOpen()
elif e == serial.writeTimeoutError:
raise labtronyx.InterfaceTimeout()
else:
raise labtronyx.InterfaceError(e.strerror)
def query(self, data, delay=None):
"""
Retrieve ASCII-encoded data from the device given a prompt.
A combination of write(data) and read()
:param data: Data to send
:type data: str
:param delay: delay (in seconds) between write and read operations.
:type delay: float
:returns: str
:raises: labtronyx.ResourceNotOpen
:raises: labtronyx.InterfaceTimeout
:raises: labtronyx.InterfaceError
"""
try:
ret_data = self.instrument.query(data)
self.logger.debug("VISA Query: %s returned: %s", data, ret_data)
return ret_data
except visa.InvalidSession:
raise labtronyx.ResourceNotOpen
except visa.VisaIOError as e:
if e.abbreviation in ["VI_ERROR_TMO"]:
raise labtronyx.InterfaceTimeout(e.description)
else:
raise labtronyx.InterfaceError(e.description)
def enumerate(self):
"""
Identify all devices known to the VISA driver and create resource objects for valid resources
"""
if self.__resource_manager is None:
raise labtronyx.InterfaceError("Interface not open")
self.logger.debug("Enumerating VISA interface")
try:
new_res_list = [
res for res in self.__resource_manager.list_resources()
if res not in self.resources_by_id
]
# Check for new resources
for resID in new_res_list:
try:
self.openResource(resID)
except labtronyx.ResourceUnavailable:
pass
except visa.VisaIOError as e:
# Exception thrown when there are no resources
self.logger.exception('VISA Exception during enumeration')
def read(self, termination=None, encoding=None):
"""
Read ASCII-formatted data from the instrument.
Reading stops when the device stops sending, or the termination characters sequence was detected. All
line-ending characters are stripped from the end of the string.
:param termination: Line termination
:type termination: str
:param encoding: Encoding
:type encoding: str
:return: str
:raises: labtronyx.ResourceNotOpen
:raises: labtronyx.InterfaceTimeout
:raises: labtronyx.InterfaceError
"""
try:
data = self.instrument.read(termination, encoding)
self.logger.debug("VISA Read: %s", data)
return data
except visa.InvalidSession:
raise labtronyx.ResourceNotOpen()
except visa.VisaIOError as e:
if e.abbreviation in ["VI_ERROR_TMO"]:
raise labtronyx.InterfaceTimeout(e.description)
else:
raise labtronyx.InterfaceError(e.description)
def flush(self):
"""
Flush the output buffer
"""
try:
return self.instrument.flush()
except serial.SerialException as e:
raise labtronyx.InterfaceError(e.strerror)
def inWaiting(self):
"""
Return the number of bytes in the receive buffer
:returns: int
:raises: InterfaceError
"""
try:
return self.instrument.inWaiting()
except serial.SerialException as e:
raise labtronyx.InterfaceError(e.strerror)
def getResource(self, resID):
"""
Attempt to open a Serial instrument. If successful, a serial resource is added to the list of known resources
and the object is returned.
:return: object
:raises: ResourceUnavailable
:raises: InterfaceError
"""
if resID in self.resources_by_id:
raise labtronyx.InterfaceError("Resource instance already exists")
try:
instrument = serial.Serial(port=resID, timeout=0)
res_obj = self.manager.plugin_manager.createPluginInstance(r_Serial.fqn, manager=self.manager,
interface=self,
resID=resID,
instrument=instrument,
logger=self.logger
)
# Signal new resource event
self.manager._publishEvent(labtronyx.EventCodes.resource.created, res_obj.uuid)
return res_obj
except (serial.SerialException, OSError) as e:
if os.name == 'nt':
# Windows implementation of PySerial does not set errno correctly
import ctypes
e.errno = ctypes.WinError().errno
if e.errno in [errno.ENOENT, errno.EACCES, errno.EBUSY]:
raise labtronyx.ResourceUnavailable('Serial resource error: %s' % resID)
else:
raise labtronyx.InterfaceError('Serial interface error [%i]: %s' % (e.errno, e.message))
def read_raw(self, size=None):
"""
Read Binary-encoded data directly from the instrument.
:param size: Number of bytes to read
:type size: int
:raises: labtronyx.ResourceNotOpen
:raises: labtronyx.InterfaceTimeout
:raises: labtronyx.InterfaceError
"""
ret = bytes()
try:
if type(self.instrument
) == pyvisa.resources.serial.SerialInstrument:
# There is a bug in PyVISA that forces a low-level call (hgrecco/pyvisa #93)
with self.instrument.ignore_warning(
pyvisa.constants.VI_SUCCESS_MAX_CNT):
if size is None:
num_bytes = self.instrument.bytes_in_buffer
chunk, status = self.instrument.visalib.read(
self.instrument.session, num_bytes)
ret += chunk
else:
while len(ret) < size:
chunk, status = self.instrument.visalib.read(
self.instrument.session, size - len(ret))
ret += chunk
return ret
else:
return self.instrument.read_raw()
except visa.InvalidSession:
raise labtronyx.ResourceNotOpen
except visa.VisaIOError as e:
if e.abbreviation in ["VI_ERROR_TMO"]:
raise labtronyx.InterfaceTimeout(e.description)
else:
raise labtronyx.InterfaceError(e.description)
def write_raw(self, data):
"""
Send Binary-encoded data to the instrument without modification
:param data: Data to send
:type data: str
:raises: labtronyx.ResourceNotOpen
:raises: labtronyx.InterfaceError
"""
try:
self.instrument.write_raw(data)
self.logger.debug("VISA Write: %s", data)
except visa.InvalidSession:
raise labtronyx.ResourceNotOpen()
except visa.VisaIOError as e:
raise labtronyx.InterfaceError(e.description)
def write(self, data):
"""
Send ASCII-encoded data to the instrument. Termination character is appended automatically, according to
`write_termination` property.
:param data: Data to send
:type data: str
:raises: labtronyx.ResourceNotOpen
:raises: labtronyx.InterfaceError
"""
try:
self.instrument.write(data)
self.logger.debug("VISA Write: %s", data)
except visa.InvalidSession:
raise labtronyx.ResourceNotOpen()
except visa.VisaIOError as e:
raise labtronyx.InterfaceError(e.description)
def write_raw(self, data):
"""
Send Binary-encoded data to the instrument. Termination character is
not included
:param data: Data to send
:type data: str
:raises: ResourceNotOpen
:raises: InterfaceTimeout
:raises: InterfaceError
"""
try:
self.instrument.write(data)
except SerialException as e:
if e == serial.portNotOpenError:
raise labtronyx.ResourceNotOpen()
elif e == serial.writeTimeoutError:
raise labtronyx.InterfaceTimeout()
else:
raise labtronyx.InterfaceError(e.strerror)
def prune(self):
"""
Close any resources that are no longer known to the VISA interface
"""
if self.__resource_manager is None:
raise labtronyx.InterfaceError("Interface not open")
try:
# Get a fresh list of resources
res_list = self.__resource_manager.list_resources()
except visa.VisaIOError:
# Exception thrown when there are no resources
res_list = []
for res_uuid, res_obj in self.resources.items():
resID = res_obj.resID
if resID not in res_list:
res_obj.close()
self.manager.plugin_manager.destroyPluginInstance(res_uuid)
self.manager._publishEvent(
labtronyx.EventCodes.resource.destroyed, res_obj.uuid)