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D.2: Data Link Layer
The Data Link Layer for Shark® 100S meters is subject to the following consider-
ations:
Control Field
The Control Byte contains several bits and a Function Code.
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® 100S meters support all of the Function Codes for DNP 3.0.
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 can take place. Unconfirmed communication is
always possible and does not require a RESET.
User Data (Function 3)
After receiving a request for USER DATA, the meter generates a Data Link
CONFIRMATION, signaling the reception of the request, before the actual request is
processed. If a response is required, it is also sent as UNCONFIRMED USER DATA.
Unconfirmed User Data (Function 4)
After receiving a request for UNCONFIRMED USER DATA, if a response is required, it is
sent as UNCONFIRMED USER DATA.
Address
DNP 3.0 allows for addresses from 0 - 65534 (0x0000 - 0xFFFE) for individual device
identification, with the address 65535 (0xFFFF) defined as an all stations address.
Electro Industries/GaugeTech
Electro Industries/GaugeTech
The Leader In Power Monitoring and Smart Grid Solutions
The Leader In Power Monitoring and Smart Grid Solutions
D: DNP 3.0 Protocol Assignments
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