Simex SLE-73, User Manual

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User manual - COUNTER SLE-73
9.3. EXAMPLES OF QUERY/ANSWER FRAMES
Examples apply for device with address 1. All values are represent hexadecimal.
Field description:
ADDR
Device address on Modbus network
FUNC Function code
REG H,L Starting address (address of first register to read/write, Hi and Lo byte)
COUNT H,L
No. of registers to read/write (Hi and Lo byte)
BYTE C
Data byte count in answer frame
DATA H,L
Data byte (Hi and Lo byte)
CRC L,H CRC error check (Hi and Lo byte)
1. Read of device ID code
ADDR FUNC REG H,L COUNT H,L CRC L,H
01 03 00 21 00 01 D4 00
The answer:
ADDR FUNC BYTE C DATA H,L CRC L,H
01 03 02 20 CC A1 D1
DATA - identification code (20CCh)
2. Change of the device address from 1 to 2 (write to reg. 20h)
ADDR FUNC REG H,L DATA H,L CRC L,H
01 06 00 20 00 02 09 C1
DATA H - 0
DATA L - new device address (2)
The answer (the same as the message):
ADDR FUNC REG H,L DATA H,L CRC L,H
01 06 00 20 00 02 09 C1
3. Change of baud rate of all devices connected to the net (BROADCAST message).
ADDR FUNC REG H,L COUNT H,L CRC L,H
00 06 00 22 00 04 29 D2
DATA H - 0
DATA L - 4, new baud rate 19200 baud
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