No data exists for extended channels.

[maple100]

I changed the source to support the expansion channel and tested it, and it is working.
Share the webpage and changed source for the expansion channel.

#Edit def append_graphtec_readings(self)

from bs4 import BeautifulSoup
from requests import get
from pandas import DataFrame

class Graphtec:

    #-----------------------------------
    def __init__(self, address, resource_manager):
        self.address = address
        self.tcpip_gl = f"TCPIP::{self.address}::8023::SOCKET"                          # TCPIP adress to contact
        self.instrument = resource_manager.open_resource(self.tcpip_gl,
                                                            write_termination='\n',
                                                            read_termination='\r\n')
        self.query_id = self.get_graphtec_idn()
        self.data = []                                                                  # Holds measurement data

    #-----------------------------------
    def append_graphtec_readings(self):
        """Find all the measurements of the channels and append to self.data list"""
        # Format URL
        address_channel_data = f"http://{self.address}/digital.cgi?chgrp=13"

        # Get http response
        response = get(address_channel_data)                        # Get response from the channel data page

        # Create response table
        soup_object = BeautifulSoup(response.text, 'html.parser')   # Create a soup object from this, which is used to create a table
        temps = soup_object.select('b')
        # Loop over table to yield formatted data
        channels_data = []
        # Holds all the found data > in format: [('CH 1', '+  10', 'degC'), (CH2 ....]
        temps = [read_tag.get_text(strip=True) for read_tag in temps]
        count = 2
        for idx, temp in enumerate(temps):
            if idx == count:
                channels_data.append(temps[idx-2:idx+1])
                count = count + 3

        # Append the data to the list
        self.data.append(channels_data)

    #-----------------------------------
    def get_graphtec_idn(self):
        """SCPI command to get IDN"""
        idn = self.instrument.query("*IDN?")
        return idn

    #-----------------------------------
    def add_channel_data_to_df(self):
        """Post processing method to format self.data list into a Pandas DataFrame"""

        name_index = 0      # Format is ['CH 1', '23.56', 'degC']
        reading_index = 1   # so index 0, 1 and 2 are, respectively channel name, value reading and unit.
        unit_index = 2

        channel_count = len(self.data[0])    # Amount of channels to loop over, might depend on Graphtec device (I have 20)
        df = DataFrame()

        # Loop over each channel
        for channel_ind in range(channel_count):

            channel_name = self.data[0][channel_ind][name_index]    # get the channel name
            channel_unit = self.data[0][channel_ind][unit_index]    # and unit
            column_name = f"GRPH {channel_name} [{channel_unit}]"   # Format column name "GRPH CH1 [degC]"

            channel_readings = []                                   # Stores the channel data > [0.0, 0.1, 0.0 ....]

            # Loop over each row and retrieve channel data
            for row in self.data:
                channel_reading = row[channel_ind][reading_index]   # Read the data of channel for this row

                # Value formatting
                if channel_reading == '-------' or channel_reading == '+++++++' or channel_reading =='BURNOUT':
                    channel_reading = None #"NaN"                                 # NaN for false values
                else:
                    channel_reading = float(channel_reading.replace(' ',''))# Float for other values, remove spaces in order to have +/-


                channel_readings.append(channel_reading)

            df[column_name] = channel_readings          # Add a new column with data

        return df