'\" t
.\"     Title: modbus_write_bits
.\"    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_WRITE_BITS" "3" "02/28/2020" "libmodbus v3\&.1\&.6" "libmodbus Manual"
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.SH "NAME"
modbus_write_bits \- write many bits
.SH "SYNOPSIS"
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\fBint modbus_write_bits(modbus_t *\fR\fB\fIctx\fR\fR\fB, int \fR\fB\fIaddr\fR\fR\fB, int \fR\fB\fInb\fR\fR\fB, const uint8_t *\fR\fB\fIsrc\fR\fR\fB);\fR
.SH "DESCRIPTION"
.sp
The \fBmodbus_write_bits()\fR function shall write the status of the \fInb\fR bits (coils) from \fIsrc\fR at the address \fIaddr\fR of the remote device\&. The \fIsrc\fR array must contains bytes set to TRUE or FALSE\&.
.sp
The function uses the Modbus function code 0x0F (force multiple coils)\&.
.SH "RETURN VALUE"
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The function shall return the number of written bits if successful\&. Otherwise it shall return \-1 and set errno\&.
.SH "ERRORS"
.PP
\fBEMBMDATA\fR
.RS 4
Writing too many bits
.RE
.SH "SEE ALSO"
.sp
\fBmodbus_read_bits\fR(3) \fBmodbus_write_bit\fR(3)
.SH "AUTHORS"
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The libmodbus documentation was written by Stéphane Raimbault <stephane\&.raimbault@gmail\&.com>