AccuEnergy AcuRev 2000, User Manual

Page: 122 / 270

114
AcuRev 2000 supports Modbus communication protocols. The infrared port supports
field meter reading; The meter supports 10/100 M Ethernet port, protocols are Modbus
TCP, SMTP, HTTP, SNMP, SNTP
1.Transmission mode
The mode of transmission defines the data structure within a frame and the rules used to
transmit data.

Coding System 8 bit

Start bit 1 bit

Data bits 8 bit

Parity No parity / odd parity / even parity

Stop bit 1bit or 2bit

Error checking CRC
2. Frame
When data frame reaches the terminal unit, it goes through the unit via a special "port", the
unit removes the data frame's header, reads the data, if there is no error, then it implements
the data's task. Afterwards, the unit puts its own data with the acquired header, and sends
back the frame to the sender. The response data frame contains: Address, Function, Data
and CRC Check. Any error will cause a failure to respond.
5.1 Modbus Protocol Introduction