"""
Driver for Agilent pressure control device.
The latter must be connected through a certain COM port (virtual or real).
Driver first initializes, then opens serial connection and reads the pressure values.
Driver handles the correct pressure to transmit
"""
import serial.tools.list_ports
import logging
import io
[docs]class Driver:
"""
Driver for Agilent pressure control device.
"""
def __init__(self, com_name):
self.com_name = com_name
self.pressure_value = 0.0
self.data_to_return = ""
self.read_str_raw = ""
def get_pressure(self, *args):
self.pressure_value = 0.0
self.data_to_return = ""
self.read_str_raw = ""
""" Opens serial connection and request/read the pressure values """
ser = serial.Serial(self.com_name,
baudrate=9600,
bytesize=serial.EIGHTBITS,
parity=serial.PARITY_NONE,
stopbits=serial.STOPBITS_ONE,
timeout=0.1)
ser_io = io.TextIOWrapper(io.BufferedRWPair(ser, ser, 1),
newline='\r',
line_buffering=True)
"""Write a command(s) to the controller and read the reply """
if args:
try:
command_full = str(args[0]) + "\r"
ser_io.write(command_full)
self.read_str_raw = ser_io.readline()
except Exception as e:
logging.exception(e)
pass
else:
ser_io.write("#000F\r") # request pressure value(s) - all connected gauges!!!
self.read_str_raw = ser_io.readline() # get only necessary numbers
ser.close()
"""Handle the received data and decide what to transmit"""
try:
for i in self.read_str_raw[1:].split(','):
try:
self.pressure_value = float(i)
if (self.pressure_value > 0.000000000001) and (self.pressure_value < 0.01):
self.data_to_return += str(self.pressure_value)+","
else:
self.data_to_return += "NAN,"
except:
if i == "underrange":
self.data_to_return += "under,"
elif i == "overrange":
self.data_to_return += "over,"
else:
self.data_to_return += "NAN,"
pass
except Exception as e:
logging.exception(e)
self.data_to_return = "NAN"
pass
try:
return str(self.data_to_return)
except Exception as e:
logging.exception(e)
pass