code: def processing_block_devices(self):
          
          # Get the list and number of Tango PB devices
          tango_db = Database()
          pb_device_class = "ProcessingBlockDevice"
          pb_device_server_instance = "processing_block_ds/1"
          pb_devices = tango_db.get_device_name(pb_device_server_instance,
                                                pb_device_class)
          LOG.info('Number of PB devices in the pool = %d', len(pb_devices))
  
          pb_device_map = []
          for pb_device_name in pb_devices:
              device = DeviceProxy(pb_device_name)
              if device.pb_id:
                  LOG.info('%s %s', pb_device_name, device.pb_id)
                  pb_device_map.append((pb_device_name, device.pb_id))
  
          return str(pb_device_map)
docs: Get list of processing block devices.