IEC60870-5-104 FAQ 
Unable to Read Tag Value, Error Code 3002 
- Check Common Address.
 - Check IOA.
 - See if there are any errors in the log.
 - It takes some time to establish connection with devices.
 - Receive a message of an unsupported type id.
 
Data Type Mismatch, Error Code 3007 
- The value read from the device does not match the data type in Neuron. For example, if the device returns a single point when IOA=100, but the Float type is configured in Neuron, such an error will occur.