'\" t
.\"     Title: modbus_set_response_timeout
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 02/28/2020
.\"    Manual: libmodbus Manual
.\"    Source: libmodbus v3.1.6
.\"  Language: English
.\"
.TH "MODBUS_SET_RESPONSE_" "3" "02/28/2020" "libmodbus v3\&.1\&.6" "libmodbus Manual"
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.SH "NAME"
modbus_set_response_timeout \- set timeout for response
.SH "SYNOPSIS"
.sp
\fBint modbus_set_response_timeout(modbus_t *\fR\fB\fIctx\fR\fR\fB, uint32_t \fR\fB\fIto_sec\fR\fR\fB, uint32_t \fR\fB\fIto_usec\fR\fR\fB);\fR
.SH "DESCRIPTION"
.sp
The \fBmodbus_set_response_timeout()\fR function shall set the timeout interval used to wait for a response\&. When a byte timeout is set, if elapsed time for the first byte of response is longer than the given timeout, an ETIMEDOUT error will be raised by the function waiting for a response\&. When byte timeout is disabled, the full confirmation response must be received before expiration of the response timeout\&.
.sp
The value of \fIto_usec\fR argument must be in the range 0 to 999999\&.
.SH "RETURN VALUE"
.sp
The function shall return 0 if successful\&. Otherwise it shall return \-1 and set errno\&.
.SH "ERRORS"
.PP
\fBEINVAL\fR
.RS 4
The argument
\fIctx\fR
is NULL, or both
\fIto_sec\fR
and
\fIto_usec\fR
are zero, or
\fIto_usec\fR
is larger than 1000000\&.
.RE
.SH "EXAMPLE"
.sp
.if n \{\
.RS 4
.\}
.nf
uint32_t old_response_to_sec;
uint32_t old_response_to_usec;

/* Save original timeout */
modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);

/* Define a new timeout of 200ms */
modbus_set_response_timeout(ctx, 0, 200000);
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
.sp
\fBmodbus_get_response_timeout\fR(3) \fBmodbus_get_byte_timeout\fR(3) \fBmodbus_set_byte_timeout\fR(3)
.SH "AUTHORS"
.sp
The libmodbus documentation was written by Stéphane Raimbault <stephane\&.raimbault@gmail\&.com>