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modbus_write_and_read_registers(3) [debian man page]

MODBUS_WRITE_AND_REA(3) 					 Libmodbus Manual					   MODBUS_WRITE_AND_REA(3)

NAME

       modbus_write_and_read_registers - write and read many registers in a single transaction

SYNOPSIS

       int modbus_write_and_read_registers(modbus_t *ctx, int write_addr, int write_nb, const uint16_t *src, int read_addr, int read_nb, const
       uint16_t *dest);

DESCRIPTION

       The modbus_write_and_read_registers() function shall write the content of the write_nb holding registers from the array src to the address
       write_addr of the remote device then shall read the content of the read_nb holding registers to the address read_addr of the remote device.
       The result of reading is stored in dest array as word values (16 bits).

       You must take care to allocate enough memory to store the results in dest (at least nb * sizeof(uint16_t)).

       The function uses the Modbus function code 0x17 (write/read registers).

RETURN VALUE

       The modbus_write_and_read_registers() function shall return the number of read registers if successful. Otherwise it shall return -1 and
       set errno.

ERRORS

       EMBMDATA
	   Too many registers requested, Too many registers to write

SEE ALSO

       modbus_read_registers(3) modbus_write_register(3) modbus_write_registers(3)

AUTHORS

       The libmodbus documentation was written by Stephane Raimbault <stephane.raimbault@gmail.com[1]>

NOTES

	1. stephane.raimbault@gmail.com
	   mailto:stephane.raimbault@gmail.com

libmodbus 3.0.3 						    05/26/2012						   MODBUS_WRITE_AND_REA(3)

Check Out this Related Man Page

MODBUS_REPLY(3) 						 Libmodbus Manual						   MODBUS_REPLY(3)

NAME

       modbus_reply - send a reponse to the received request

SYNOPSIS

       *int modbus_reply(modbus_t *ctx, const uint8_t *req, int req_length, modbus_mapping_t *mb_mapping);

DESCRIPTION

       The modbus_reply() function shall send a response to received request. The request req given in argument is analyzed, a response is then
       built and sent by using the information of the modbus context ctx.

       If the request indicates to read or write a value the operation will done in the modbus mapping mb_mapping according to the type of the
       manipulated data.

       If an error occurs, an exception response will be sent.

       This function is designed for Modbus server.

RETURN VALUE

       The modbus_reply() function shall return the length of the response sent if successful. Otherwise it shall return -1 and set errno.

ERRORS

       EMBMDATA
	   Sending has failed

       See also the errors returned by the syscall used to send the response (eg. send or write).

SEE ALSO

       modbus_reply_exception(3) libmodbus(7)

AUTHORS

       The libmodbus documentation was written by Stephane Raimbault <stephane.raimbault@gmail.com[1]>

NOTES

	1. stephane.raimbault@gmail.com
	   mailto:stephane.raimbault@gmail.com

libmodbus 3.0.3 						    05/26/2012							   MODBUS_REPLY(3)
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