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V: 1.0 Revised: Jan. 2018
Chapter 5: Communication
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This chapter introduces users on how to communicate with the AcuRev 1310 Series meter
through the Modbus communication protocol. Knowledge of the Modbus communication pro-
tocol would be beneficial for users who read this chapter.
The chapter’s contents include the Modbus protocol, communication format, and application
of the AcuRev 1310 series meter.
5.1 Modbus Protocol Information
5.1.1. Transmission Mode
The mode of transmission defines the data structure within a frame and the rules used to trans-
mit data.
Coding System
8 bit
Start Bit
1 bit
Data Bits
8 bit
Parity
No parity/ odd parity/ even parity
Stop bit
1 bit or 2 bit
Error checking
CRC
5.1.2. Frame
When the data frame reaches the AcuRev 1310 series meter (slave device), the meter removes
the data frame’s header, and reads the data. If there is no error, then the meter will implement
the data’s task. Once the task is completed, the meter will put its own data with the acquired
header and send back the frame to the master device that queried the meter. The response
data frame contains the address, function, data and CRC check. An error will cause the re-
sponse to fail.
Table 5-1 Data Frame Format
Address
Function
Data
Check
8-Bits
8-Bits
N x 8-Bits
16-Bits
Address Field
The address field is the data at the start of the frame. It is composed of 8 bits (1 byte) and corre-
sponds to the device address. It has a decimal value ranging from 1-247.
The master device addresses the slave device by placing the slave device address in the address
field of the message. When the slave sends its response, it places its own address in the ad-
dress field of response to let the master know which slave is responding.