ELNet LT - CHAPTER 6 - COMMUNICATION; 6.1 - MODBUS Framing; 6.1.1-RTU Transmission Mode

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CHAPTER 6 — COMMUNICATION
MODBUS Protocol
The ELNet LT Energy & Powermeter has a serial interface
port allowing direct interface with an external communication
network supporting the MODBUS Protocol.
MODBUS is an Industry Standard, widely known and commonly
used communications protocol. Using MODBUS provides
communication between a PC and up to 247 Powermeter slaves on a
common line - the PC being the master and the powermeters the
slaves. The PC initiates the transaction (either a query or broadcast)
and the Powermeter/s responds. Powermeters respond to the master
PC’s request, but will not initiate any transmission on its own. The
PC sends a single Query transaction and the Powermeter responds in
a single response frame and is capable of only one query and one
response at a time.
6.1 — MODBUS Framing
6.1.1— RTU Transmission Mode
MODBUS uses the standard Remote Terminal Unit (RTU)
transmission mode. RTU mode sends data in 8-bit binary EVEN
parity or 8-bit binary NO parity data format. For the ELNet LT
Energy & Powermeter to successfully communicate, choose one in
the communication Set Up.