code: def build_kal_scan_channel_string(kal_bin, channel, args):
      
      option_mapping = {"gain": "-g",
                        "device": "-d",
                        "error": "-e"}
      base_string = "%s -v -c %s" % (kal_bin, channel)
      base_string += options_string_builder(option_mapping, args)
      return(base_string)
docs: Return string for CLI invocation of kal, for channel scan.