AccuEnergy AcuDC 241, User Manual

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Data start reg hi: Start register address, high byte
Data start reg lo: Start register address, low byte
Data #of reg hi: Number of registers, high byte
Data #of reg lo: Number of registers, low byte
CRC16 hi: CRC high byte
CRC16 lo: CRC low byte
1. Read Relay Output Status(Function Code 01)
Query
The master device sends query frame to the salve deivce. Function Code 01 allows users
to acquire the relay output status (1=ON, 0=OFF) of the slave device with the specified
address. Along with slave device address and function code, query frame must contain the
relay register starting address and the number of registers to be read.
AcuDC 240 relay output address starts from 0000H(Relay1=0000H,Relay2=0001H)
Table 4.4 depicts reading Relay 1 and Relay 2 status from slave address 17.
Addr Fun
DO start
reg hi
DO start reg
lo
DO #of regs
hi
DO #of regs
lo
CRC16
Hi
CRC16
Lo
11H 01H 00H 00H 00H 02H BFH 5BH
Table 4-4 Query frame of reading Relay Output status
Response
The slave device anwsers the master device's query. The response frame contains slave
device address, function code, data quantity and CRC check. Each relay utilizes one bit(1 =
ON , 0 = OFF). Table 4-5 depicts the response frame.