Communication with PCF8574 (Located in LCD's I2C backpack)

Use serial Port with the following parameters:
1000000,n,8,1 (COM4 in this case)
The Script:
#
desc: LCD
#
reboot command
Sende
"_" "\x01" 5
Sleep
1
#
send echo byte
Sende
"e\x41" "\x01" 5
#
transmit status info
Sende
"?" "\x01" 5
#
send START
Sende
"s\x4e"
"\x01" 5
#
write n bytes - c1 actually means SEND 2
bytes
# to send
a 3, we need to send it dup with suffix:
# 4 and 0
Sende
"\xc1\x34\x30"
"\x01" 5
Sleep
1
#
write n bytes - c7 actually means SEND 8 bytes
Sende
"\xc7\x34\x30\x34\x30\x24\x20\x24\x20"
"\x01" 5
Sende
"\xc1\xc4\xc0"
"\x01" 5
Sende
"\xc3\x04\x00\x14\x10"
"\x01" 5
Sende
"\xc3\x04\x00\xc4\xc0"
"\x01" 5
Sende
"\xc3\x04\x00\x64\x60"
"\x01" 5
#
send STOP
Sende
"p" "" 1
Sende
"s\x4e"
"\x01" 5
Sende
"\xc3\x45\x41\x15\x11"
"\x01" 5
Sende
"p" "" 1