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V: 1.0 Revised: Aug. 2017
AcuRev 1312
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DIN-Rail Power Meter
field of response to let the master know which slave is responding.
Function Field: When a query is sent from the master to a slave device the function code field
tells the slave what kind of action to perform.
Table 5.2 Function Code
Function Code
Meaning
Action
03
Read Holding Register
Obtain current value of 1 or more registers
16
Preset register
Set value of 1 or more register
Data Field: The data field contains the data that the slave device needs in order to complete the
request. This data may be a numerical value, address or setting. For example, the function code
tells the slave device to read one register however the data field specifies reading from which
register and how many registers to read.
Error Check Field: This field allows for error checks to be performed by both master and slave
devices. Sources of errors such as electrical noise and other interferences can cause the data to
be changed while it is being transmitted from one device to other. The error check ensures that
the master or slave devices do not respond to the distorted data during the transmission. The
error check rule used is the 16 bit Cyclic Redundancy Check (CRC 16).
5.2 Communication Format
Addr Fun
Data start
register hi
Data start
register low #of registers hi #of registers low CRC16 hi CRC16 low
06H 03H
00H
00H
00H
21H
84H
65H
Fun: Function code
Data start reg hi: High byte of starting register address
Data start reg lo: Low byte of starting register address
Data #of regs hi: High byte of number of registers
Data #of regs lo: Low byte of number of registers
1. Read Data (Function Code 03H)
This function code allows the user to obtain the measurement data from the AcuRev 1312.
Below is a example of an query for reading three of the AcuRev 1312’s energy parameters. The
query is requesting the total active energy, tariff 1 active energy and tariff 2 active energy from
the meter with device address of 17. The data type of the energy parameters are double words.
