I want to built a function that sends a request from ModBus to serial in hex. I more o less have a working function but have two issues.
Issue 1
[b'\x06', b'\x1c', b'\x00!', b'\r', b'\x1e', b'\x1d\xd3', b'\r', b'\n', b'\x1e', b'\x1d']
I cant remove this part b'\r', b'\n', using the .split('\r \n') method since It's not a string.
Issue 2 When getting a value from holding register 40 (33) and i try to use the .to_bytes() method I keep getting b'\x00!', b'\r' and I'm expecting b'\x21'
r = client.read_holding_registers(40)
re = r.registers[0]
req = re.to_bytes(2, 'big')
My functions to generate my request and to send trough pyserial.
def scanned_code():
code = client.read_holding_registers(0)
# code2= client.re
r = code.registers[0]
return r
def send_request(data):
""" Takes input from create_request() and sends data to serial port"""
try:
for i in range(data):
serial_client.write(data[i])
# serial_client.writelines(data[i])
except:
print('no se pudo enviar el paquete <<<--------------------')
def create_request(job):
""" Request type is 33 looks for job
[06]
[1c]
req=33[0d][0a]
job=30925[0d][0a][1e]
[1d]
"""
r = client.read_holding_registers(40)
re = r.registers[0]
req = re.to_bytes(2, 'big')
num = job.to_bytes(2, 'big')
data = [
b'\x06',
b'\x1C',
req,
b'\x0D',
b'\x1E',
num,
b'\x0D',
b'\x0A',
b'\x1E',
b'\x1D'
]
print(data)
while True:
# verify order_trigger() is True.
while order_trigger() != False:
print('inside while loop')
# set flag coil back to 0
reset_trigger()
# get Job no.
job = scanned_code()
# check for JOB No. dif. than 0
if job != 0:
print(scanned_code())
send_request(create_request(job))
# send job request to host to get job data
# send_request()
# if TRUE send job request by serial to DVI client
# get job request data
# translate job request data to modbus
# send data to plc
else:
print(' no scanned code')
break
time.sleep(INTERNAL_SLEEP_TIME)
print('outside loop')
time.sleep(EXTERNAL_SLEEP_TIME)
As an additional question is this the proper way of doing things?