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16
START
ADDRESS
Pause
1 byte
>3,5 bytes
The following functions are sustained:
1. Read holding Register
Reads one or more registers from the slave.
2. Preset Single Register
Changes a register in the slave.
3. Preset Multiple Regs
Changes several registers in the slave.
4. Report Slave ID
Reads the slave ID of the slave.
The individual registers as well as the calculations of the corresponding
register addresses are described in chapter 4.4. The J-bus register
address is always used (i.e. also with Modbus) within the telegrams.
4.3.1 READ hOLDInG REGISTERS (0X03)
With this telegram the master can read out one or more registers (function
code 0x03). The registers must lie in series.
Example:
Registers 72 + 128 (load voltage chapter 4.4, Controller 1) are to be read out
from the bus module with the address 100. (72 + 128 = 200, no overflow into
high byte).
Inquiry:
ADDRESS
fUnCTIOn
100
3
Response:
ADDRESS
fUnCTIOn
100
3
Error:
Should the address of the register to be read out lie outside the address
location, the reply Exception Response „ILLEGAL DATA
ADDRESS" is transmitted (see chapter 4.3.5).
fUnCTIOn
DATA
ByTES
1 byte
x bytes
REGISTER
nUMBER
0, 200
0, 2
nO.
DATA
ByTES
4
250, 184, 70, 23
CRC
EnD
2 bytes
Pause
>3,5 bytes
CRC
76, 00
CRC
13, 166
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