"""

So how to change a bool value?

1) Read out the _bytearray your boolean values are in.

2) In this byte_array you need to find the byte (byteindex)

3) Find the bit in this byte (bitindex) so you can

4) set the correct value with utility function set_bool which does all the hard work.

set_bool(_bytearray = data which you read out before.., byte_index, bool_index, value),

5) write back the changed bytearray back to the PLC.

A round trip wil take 5ms.

The example code

https://github.com/gijzelaerr/python-snap7/blob/master/example/

the minimun amount of data being read or written to a plc is 1 byte.

"""

import snap7

plc = snap7.client.Client()

plc.connect('192.168.200.24', 0, 3)

# In this example boolean in DB 31 at byte 120 and bit 5 is changed. = 120.5

reading = plc.db_read(31, 120, 1) # read 1 byte from db 31 staring from byte 120

snap7.util.set_bool(reading, 0, 5) # set a value of fifth bit

plc.db_write(reading, 31, 120, 1) # write back the bytearray and now the boolean value is changed in the PLC.

# NOTE you could also use the read_area and write_area functions.

# then you can specify an area to read from:

# https://github.com/gijzelaerr/python-snap7/blob/master/snap7/types.py

from snap7.types import areas # noqa: E402

# play with these functions.

plc.read_area(area=areas['MK'], dbnumber=0, start=20, size=2)

data = bytearray()

snap7.util.set_int(data, 0, 127)

plc.write_area(area=areas['MK'], dbnumber=0, start=20, data=data)

# read the client source code!

# and official snap7 documentation