Specifications

e Electro Industries/GaugeTech Doc # E145701 D-1
Appendix D
DNP 3.0 Protocol Assignments for Shark
D.1: DNP Implementation
Q
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.
Q
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.
Q
Communication Parameters
Shark 100 meters communicate in DNP 3.0 using the following communication settings:
• 8 Data Bits
• No Parity
• 1 Stop Bit
Q
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
Q
The Data Link Layer as implemented on Shark meters is subject to the following considerations:
Q
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 ).
Q
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