old_contents: """
  This module provides classes for interfacing with analog plugins.
  """
  import json
  from myDevices.plugins.manager import PluginManager
  from myDevices.utils.logger import info
  
  
  class AnalogInput():
      """Reads data from an analog input."""
  
      def __init__(self, adc_name):
          """Initializes the analog input.
          
          Arguments:
              adc_name: Name of analog-to-digital converter plugin in the format 'plugin_name:section'
          """
          self.adc_name = adc_name
          self.adc = None
          self.read_args = {}
          self.pluginManager = PluginManager()
          self.set_adc()
      
      def set_adc(self):
          """Sets the ADC plugin."""
          if not self.adc:
              self.adc = self.pluginManager.get_plugin_by_id(self.adc_name)
              self.read_args = json.loads(self.adc['read_args'])
  
      def read_value(self, channel, data_type=None):
          """Read the data value on the specified channel."""
          self.set_adc()
          value = getattr(self.adc['instance'], self.adc['read'])(channel, data_type=data_type, **self.read_args)
          return value
         
      def read_float(self, channel):
          """Read the float value on the specified channel."""
          return self.read_value(channel, 'float')
      
      def read_volt(self, channel):
          """Read the voltage on the specified channel."""
          return self.read_value(channel, 'volt')
  
new_contents: """
  This module provides classes for interfacing with analog plugins.
  """
  import json
  from myDevices.plugins.manager import PluginManager
  from myDevices.utils.logger import info, debug
  
  
  class AnalogInput():
      """Reads data from an analog input."""
  
      def __init__(self, adc):
          """Initializes the analog input.
          
          Arguments:
              adc: Analog-to-digital converter plugin ID in the format 'plugin_name:section', e.g. 'cayenne-mcp3xxx:MCP'
          """
          self.adc_name = adc
          self.adc = None
          self.read_args = {}
          self.pluginManager = PluginManager()
          self.set_adc()
      
      def set_adc(self):
          """Sets the ADC plugin."""
          if not self.adc:
              self.adc = self.pluginManager.get_plugin_by_id(self.adc_name)
              self.read_args = json.loads(self.adc['read_args'])
  
      def read_value(self, channel, data_type=None):
          """Read the data value on the specified channel."""
          self.set_adc()
          try:
              value = getattr(self.adc['instance'], self.adc['read'])(channel, data_type=data_type, **self.read_args)
          except ValueError as e:
              debug(e)
              value = None
          return value
         
      def read_float(self, channel):
          """Read the float value on the specified channel."""
          return self.read_value(channel, 'float')
      
      def read_volt(self, channel):
          """Read the voltage on the specified channel."""
          return self.read_value(channel, 'volt')
  
subject: Modify AnalogInput initialization, add exception handling.