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DNP 3.0 Protocol Assignments for Shark
D.1: DNP Implementation
PHYSICAL LAYER
The Shark 100 meter is capable of using RS-485 as the physical layer. This is accomplished by
connecting a PC to the Shark with the RS-485 connection on the back face of the meter.
RS-485
RS-485 provides multi-drop network communication capabilities. Multiple meters may be placed on
the same bus, allowing for a Master device to communicate with any of the other devices.
Appropriate network configuration and termination should be evaluated for each installation to
insure optimal performance.
Communication Parameters
Shark 100 meters communicate in DNP 3.0 using the following communication settings:
•
8 Data Bits
•
No Parity
•
1 Stop Bit
Baud Rates
Shark 100 meters are programmable to use several standard baud rates, including:
•
9600 Baud
•
19200 Baud
•
38400 Baud
•
57600 Baud
D.2: Data Link Layer
The Data Link Layer as implemented on Shark meters is subject to the following considerations:
Control Field
The Control Byte contains several bits and a Function Code. Specific notes follow.
Control Bits
Communication directed to the meter should be Primary Master messages ( DIR = 1, PRM = 1 ).
Response will be primary Non-Master messages ( DIR = 0, PRM = 1 ). Acknowledgment will be
Secondary Non-Master messages ( DIR = 0, PRM = 0 ).
Function Codes
Shark meters support all of the Function Codes for DNP 3.0. Specific notes follow.
Reset of Data Link ( Function 0 )
Before confirmed communication with a master device, the Data Link Layer must be reset. This is
necessary after a meter has been restarted, either by applying power to the meter or reprogramming
the meter. The meter must receive a RESET command before confirmed communication may take
e
Electro Industries/GaugeTech
Appendix D
Doc # E145701
D-1
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