def wait_for_srq(self, timeout=25):
"""Wait for a serial request (SRQ) coming from the instrument.
Note that this method is not ended when *another* instrument signals an
SRQ, only *this* instrument.
Parameters:
timeout -- (optional) the maximal waiting time in seconds. The default
value is 25 (seconds). "None" means waiting forever if necessary.
"""
vpp43.enable_event(self.vi, VI_EVENT_SERVICE_REQ, VI_QUEUE)
if timeout and not(0 <= timeout <= 4294967):
raise ValueError, "timeout value is invalid"
starting_time = time.clock()
while True:
if timeout is None:
adjusted_timeout = VI_TMO_INFINITE
else:
adjusted_timeout = int((starting_time + timeout - time.clock())
* 1000)
if adjusted_timeout < 0:
adjusted_timeout = 0
event_type, context = \
vpp43.wait_on_event(self.vi, VI_EVENT_SERVICE_REQ,
adjusted_timeout)
vpp43.close(context)
if self.stb & 0x40:
break
vpp43.discard_events(self.vi, VI_EVENT_SERVICE_REQ, VI_QUEUE)
def __init__(self, gpib_identifier, board_number=0, **keyw):
"""Class constructor.
parameters:
gpib_identifier -- if it's a string, it is interpreted as the
instrument's VISA resource name. If it's a number, it's the
instrument's GPIB number.
board_number -- (default: 0) the number of the GPIB bus.
Further keyword arguments are passed to the constructor of class
Instrument.
"""
_warn_for_invalid_keyword_arguments(keyw, ("timeout", "term_chars",
"chunk_size", "lock",
"delay", "send_end",
"values_format"))
if isinstance(gpib_identifier, int):
resource_name = "GPIB%d::%d" % (board_number, gpib_identifier)
else:
resource_name = gpib_identifier
Instrument.__init__(self, resource_name, **keyw)
# Now check whether the instrument is really valid
if self.interface_type != VI_INTF_GPIB:
raise ValueError, "device is not a GPIB instrument"
vpp43.enable_event(self.vi, VI_EVENT_SERVICE_REQ, VI_QUEUE)
def wait_for_srq(self, timeout=25):
"""Wait for a serial request (SRQ) coming from the instrument.
Note that this method is not ended when *another* instrument signals an
SRQ, only *this* instrument.
Parameters:
timeout -- (optional) the maximal waiting time in seconds. The default
value is 25 (seconds). "None" means waiting forever if necessary.
"""
vpp43.enable_event(self.vi, VI_EVENT_SERVICE_REQ, VI_QUEUE)
if timeout and not(0 <= timeout <= 4294967):
raise ValueError, "timeout value is invalid"
starting_time = time.clock()
while True:
if timeout is None:
adjusted_timeout = VI_TMO_INFINITE
else:
adjusted_timeout = int((starting_time + timeout - time.clock())
* 1000)
if adjusted_timeout < 0:
adjusted_timeout = 0
event_type, context = \
vpp43.wait_on_event(self.vi, VI_EVENT_SERVICE_REQ,
adjusted_timeout)
vpp43.close(context)
if self.stb & 0x40:
break
vpp43.discard_events(self.vi, VI_EVENT_SERVICE_REQ, VI_QUEUE)
def __init__(self, gpib_identifier, board_number=0, **keyw):
"""Class constructor.
parameters:
gpib_identifier -- if it's a string, it is interpreted as the
instrument's VISA resource name. If it's a number, it's the
instrument's GPIB number.
board_number -- (default: 0) the number of the GPIB bus.
Further keyword arguments are passed to the constructor of class
Instrument.
"""
_warn_for_invalid_keyword_arguments(keyw, ("timeout", "term_chars",
"chunk_size", "lock",
"delay", "send_end",
"values_format"))
if isinstance(gpib_identifier, int):
resource_name = "GPIB%d::%d" % (board_number, gpib_identifier)
else:
resource_name = gpib_identifier
Instrument.__init__(self, resource_name, **keyw)
# Now check whether the instrument is really valid
if self.interface_type != VI_INTF_GPIB:
raise ValueError, "device is not a GPIB instrument"
vpp43.enable_event(self.vi, VI_EVENT_SERVICE_REQ, VI_QUEUE)
def __init__(self, gpib_identifier, board_number=0, **keyw):
_warn_for_invalid_keyword_arguments(keyw, ("timeout", "term_chars",
"chunk_size", "lock",
"delay", "send_end",
"values_format"))
if isinstance(gpib_identifier, int):
resource_name = "GPIB%d::%d" % (board_number, gpib_identifier)
else:
resource_name = gpib_identifier
Instrument.__init__(self, resource_name, **keyw)
# Now check whether the instrument is really valid
if self.interface_type != VI_INTF_GPIB:
raise ValueError("device is not a GPIB instrument")
vpp43.enable_event(self.vi, VI_EVENT_SERVICE_REQ, VI_QUEUE)
