1MODBUS_WRITE_AND_REA(3) Libmodbus Manual MODBUS_WRITE_AND_REA(3)
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6 modbus_write_and_read_registers - write and read many registers in a
7 single transaction
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10 int modbus_write_and_read_registers(modbus_t *ctx, int write_addr, int
11 write_nb, const uint16_t *src, int read_addr, int read_nb, const
12 uint16_t *dest);
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15 The modbus_write_and_read_registers() function shall write the content
16 of the write_nb holding registers from the array src to the address
17 write_addr of the remote device then shall read the content of the
18 read_nb holding registers to the address read_addr of the remote
19 device. The result of reading is stored in dest array as word values
20 (16 bits).
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22 You must take care to allocate enough memory to store the results in
23 dest (at least nb * sizeof(uint16_t)).
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25 The function uses the Modbus function code 0x17 (write/read registers).
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28 The modbus_write_and_read_registers() function shall return the number
29 of read registers if successful. Otherwise it shall return -1 and set
30 errno.
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33 EMBMDATA
34 Too many registers requested, Too many registers to write
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37 modbus_read_registers(3) modbus_write_register(3)
38 modbus_write_registers(3)
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41 The libmodbus documentation was written by Stéphane Raimbault
42 <stephane.raimbault@gmail.com[1]>
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45 1. stephane.raimbault@gmail.com
46 mailto:stephane.raimbault@gmail.com
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50libmodbus 3.0.8 07/31/2019 MODBUS_WRITE_AND_REA(3)