Cannot get reply from Markem print&apply system using sockets with CimComms protocol

Question

Cannot get reply from a CimPak300 print & apply equipment, from Markem Imaje, using CimComms communication protocol. I can connect with the equipment on Ethernet, using sockets, I send messages but it doesn't respond. Maybe I'm doing something wrong when sending the message to the equipment.

So I'm using Python 3.9.4 and here is my test script:

import socket


# function to calculate header checksum
def head_check(frame_header):
    frame_header_lenght = len(frame_header)
    i = 0
    hexintdata = []
    while i < frame_header_lenght:
        j = i + 2
        hexintdata.append(hex(int(frame_header[i:j], 16)))
        i += 2
    sum = 0
    for j in hexintdata:
        k = int(j, 16)
        sum = sum + k
    ffvalue = 0xff
    checksum = ffvalue - sum
    checksum_decoded = hex((checksum + (1 << 32)) % (1 << 32))
    header_checksum = checksum_decoded[-2:]
    return header_checksum


labeler_connect_status = False
# starting a socket object and connect to CimPak300
s = socket.socket()
while True:
    if not labeler_connect_status:
        try:
            s.connect((TCP_IP, TCP_PORT))
            labeler_connect_status = True
            print('CONNECTED!')
        except Exception as e:
            print(f'ERROR_LOG_LABELER: {e}')
            labeler_connect_status = False

    # send data to labeler
    h_data = input('Insert message in hex (q for quit): ')
    if h_data == 'q':
        s.close()
        break
    else:
        h_checksum = head_check(h_data)
        print(f'Calculating header checksum: {h_checksum}')
        h_data = h_data + h_checksum
        b_data = bytes.fromhex(h_data)
        print(f'Data in bytes: {b_data}')
        print('Sending message to labeler...')
        s.send(b_data)
        print('Data sent!')
        print('waiting for response...')
        message = s.recv(1024)
        dec = message.hex()
        print(f'Response: {dec}')
        print(f'Message: {message}')

I test the data I send with Hercules and it seems right to me, but the P&A system doesn't reply. I try with poll for request message and with other messages with header only.

"The Host uses this command to determine if a printer requires information. The Host is always themaster. The individual printers will not broadcast any data over the network unless they are asked to do so. This may cause a problem when the printer requires information from the Host. To overcome this, the Host should send a ‘Poll for Request’ message approximately every ½ second. The printer treats this message as a “Do you require anything?” message. The Poll for Request message is:

<01hex> SOH - Start Character.
<81hex> Printer Node Number.
<A0hex> Poll for Request
<0> Data section length is 0
<0>
<Header Checksum> Single byte header checksum. See section 5.1.

If the printer needs something, it will respond with the appropriate message. For instance, if it requires a file, it will respond with a ‘Request File Transfer’ message (A3hex)). If it requires nothing then it will respond with an ‘Acknowledge’ message (A1hex)."

from CimComms documentation

What I'm doing wrong here?

Cannot get reply from Markem print&apply system using sockets with CimComms protocol

0 Answers0