def _send_and_read(self, message):
'''
Send <message> to the device and read answer.
Raises an error if one occurred
Returns a list of bytes
Input:
message (string) : string conform the IVVI protocol
Output:
data_out_numbers (int[]) : return message
'''
logging.debug('Sending %r', message)
# clear input buffer
visafunc.read_all(self._vi)
vpp43.write(self._vi, message)
# In stead of blocking, we could also poll, but it's a bit slower
# print visafunc.get_navail(self._vi)
# if not visafunc.wait_data(self._vi, 2, 0.5):
# logging.error('Failed to receive reply from IVVI rack')
# return False
data1 = visafunc.readn(self._vi, 2)
data1 = [ord(s) for s in data1]
# 0 = no error, 32 = watchdog reset
if data1[1] not in (0, 32):
logging.error('Error while reading: %s', data1)
data2 = visafunc.readn(self._vi, data1[0] - 2)
data2 = [ord(s) for s in data2]
return data1 + data2
def _send_and_read(self, message):
'''
Send <message> to the device and read answer.
Raises an error if one occurred
Returns a list of bytes
Input:
message (string) : string conform the IVVI protocol
Output:
data_out_numbers (int[]) : return message
'''
logging.debug('Sending %r', message)
# clear input buffer
visafunc.read_all(self._vi)
vpp43.write(self._vi, message)
# In stead of blocking, we could also poll, but it's a bit slower
# print visafunc.get_navail(self._vi)
# if not visafunc.wait_data(self._vi, 2, 0.5):
# logging.error('Failed to receive reply from IVVI rack')
# return False
data1 = visafunc.readn(self._vi, 2)
data1 = [ord(s) for s in data1]
# 0 = no error, 32 = watchdog reset
if data1[1] not in (0, 32):
logging.error('Error while reading: %s', data1)
data2 = visafunc.readn(self._vi, data1[0] - 2)
data2 = [ord(s) for s in data2]
return data1 + data2
def read(self):
data = visafunc.read_all(self._vi)
ret = ''
for c in data:
ret += '%02x,' % c
print 'Read %d bytes' % (len(data), )
print 'Data: %s' % (ret, )