AccuEnergy AcuRev 2000, User Manual

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Table 5-17
Code Meaning Action
01 Read Relay Output Status Obtain current status of Relay Output
02 Read Digital Input(DI) Status Obtain current status of Digital Input
03 Read Data Obtain current binary value in one or more registers
05 Control Single Relay Output Force Relay to a state of on or off
16 Write Multiple-registers
Place specific value into a series of consecutive
multiple-registers
d. Data Field
The data field is constructed using sets of two hexadecimal digits, in the range of 00 to
FF hexadecimal. The data field of messages sent from a master to slave devices contains
additional information which the slave must use to take the action defined by the function
code. This can include items like discrete and register addresses, the quantity of items to be
handled, and the count of actual data bytes in the field. For example, if the master requests
a slave to read a group of holding registers (function code 03), and the data field specifies
the starting register and how many registers are to be read. If the master writes to a group
of registers in the slave (function code 10 hexadecimal), the data field specifies the starting
register, how many registers to write, the count of data bytes to follow in the data field, and
the data to be written into the registers.
2. Format of communication
Explanation of frame
Table 5-18
Transaction
identifier hi
Transaction
identifier lo
Protocol
identifier hi
Protocol
identifier lo
Length hi Length lo
Unit
identifier
00H 00H 00H 00H 00H 06H 01H
Fun Data start reg hi Data start reg lo Data #of regs hi Data #of regs lo
03H 40H 00H 00H 48H