# Opcode: DGN
# Priority: Low
# Services: MNS
# Parameters: NN (2 bytes) Node number, ServiceIndex (1 bytes) Index into the list of services, DiagnosticCode (1 bytes) Diagnostic data code, DiagnosticVal (2 bytes) Diagnostic data value
# Conditions: 
# Direction: From module
# States / Modes: 
# Result: requested diagnostic of the specified service.