read_MCA.py

# Read data coming from the REM 500 Neutron Survey Meter through a RS-232 serial cable

# Authors: Leo Borrel, Sophie Middleton
# Date: 2022-10-31


import serial
import binascii
import math
from time import sleep


# Variables that can be changed in the script

# Enable test mode to turn on the check source at the beginning of the run and turn it off at the end
test_mode = False
# total runtime (in seconds)
runtime = 600 #seconds
# split time: how often the data are saved in separate files (in seconds)
split_time = 60 #seconds



# Set up port
# ser = serial.Serial('/dev/tty.usbserial-AB0K01H7',9600,timeout=100) # Sophie's Macbook
ser = serial.Serial('/dev/ttyUSB0',9600,timeout=100) # Leo's laptop (centOS)

ser.bytesize = serial.EIGHTBITS
ser.parity = serial.PARITY_NONE
ser.stopbits = serial.STOPBITS_ONE


# Create the main output text files
outputfile = open("data/count_data.txt", "w")
channelfile = open("data/channel_data.txt", "w")

# Create the multiple output files for the split time
n_split = math.ceil(runtime / split_time)

# Check if port is open
try:
    ser.isOpen()
    print("is open")
except:
    print("error: port is close")
    exit()


# Available commands to send
go = 'G'.encode('utf-8') # start the run
stop = 'S'.encode('utf-8') # stop the run
check = 'C'.encode('utf-8') # turn on and off the source in the detector
reset = 'R'.encode('utf-8') # reset data and timer
dump = 'DA'.encode('utf-8') # Dump the data for each channel

dump_read = 'D\r\n'.encode('utf-8') # printed output that separates the count readout from the data dump

# Read/Write
if(ser.isOpen()):
    serial_string = ""
    try:
        # Reset data and start the run
        ser.write(reset)
        ser.write(go)
        if test_mode == True:
            ser.write(check)

        # read data for the set runtime
        t = 0
        split = 1
        while (t <= runtime):
            split_filename = "data/count_data_split" + str(split) + ".txt"
            split_file = open(split_filename, "w")
            while(t <= split * split_time):
                # read an entire line of data containing the timestamp and the number of counts in hex format
                serial_string = ser.readline()
                print(serial_string)
                # save the data to the main output file and the split one
                outputfile.write(serial_string.decode('utf-8'))
                split_file.write(serial_string.decode('utf-8'))
                # the REM 500 sends data every second so wait for the new line of data to come
                sleep(1)
                t = t + 1
            split_file.close()
            split = split + 1

        # stop the run and turn off the source (if it has been turned on)
        ser.write(stop)
        if test_mode == True:
            ser.write(check)
        # dump the channel data
        ser.write(dump)

        # Because the commands sent to the REM 500 are part of the output, usually there is a couple of data lines missing that we need to read now
        # read all the lines until the command to send the data dump is read
        while (serial_string != dump_read):
            serial_string = ser.readline()
            print(serial_string)
            outputfile.write(serial_string.decode('utf-8'))

        # read the data for each one of the 256 channel and save them in the other output file
        for i in range(256):
            serial_string = ser.readline()
            print(serial_string)
            channelfile.write(serial_string.decode('utf-8'))

        # The line right after the channel dump is supposed to be the number of counts with the timestamp
        serial_string = ser.readline()
        print('remaining: ', serial_string)
    except Exception as err:
        print("Error: cannot read/write:", err)
else:
    print("Error: cannont open port")


# close text file
outputfile.close()
channelfile.close()