MODBUS_CLOSE(3) Libmodbus Manual MODBUS_CLOSE(3)NAME
modbus_close - close a Modbus connection
SYNOPSIS
void modbus_close(modbus_t *ctx);
DESCRIPTION
The modbus_close() function shall close the connection established with the backend set in the context.
RETURN VALUE
There is no return value.
EXAMPLE
modbus_t *ctx;
ctx = modbus_new_tcp("127.0.0.1", 502);
if (modbus_connect(ctx) == -1) {
fprintf(stderr, "Connection failed: %s
", modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
modbus_close(ctx);
modbus_free(ctx);
SEE ALSO modbus_connect(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_CLOSE(3)
Check Out this Related Man Page
MODBUS_NEW_TCP(3) Libmodbus Manual MODBUS_NEW_TCP(3)NAME
modbus_new_tcp - create a libmodbus context for TCP/IPv4
SYNOPSIS
modbus_t *modbus_new_tcp(const char *ip, int port);
DESCRIPTION
The modbus_new_tcp() function shall allocate and initialize a modbus_t structure to communicate with a Modbus TCP/IPv4 server.
The ip argument specifies the IP address of the server to which the client wants etablish a connection.
The port argument is the TCP port to use. Set the port to MODBUS_TCP_DEFAULT_PORT to use the default one (502). It's convenient to use a
port number greater than or equal to 1024 because it's not necessary to have administrator privileges.
RETURN VALUE
The modbus_new_tcp() function shall return a pointer to a modbus_t structure if successful. Otherwise it shall return NULL and set errno to
one of the values defined below.
ERRORS
EINVAL
An invalid IP address was given.
EXAMPLE
modbus_t *ctx;
ctx = modbus_new_tcp("127.0.0.1", 1502);
if (ctx == NULL) {
fprintf(stderr, "Unable to allocate libmodbus context
");
return -1;
}
if (modbus_connect(ctx) == -1) {
fprintf(stderr, "Connection failed: %s
", modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
SEE ALSO modbus_new_rtu(3)modbus_free(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_NEW_TCP(3)
I have a huge matrix file containing some 1.5 million rows and 6000 columns. The matrix looks something like this:
1 2 3
4 5 6
7 8 9
3 4 5
I want to add all the numbers in the columns of this matrix and display the result to my stdout. This means that the numbers in the first column are:
... (2 Replies)
Hi,
Just trying to get to grips with sed and awk for some reporting for work and I need some assistance:
I have a file that lists policy names on the first line and then on the second line whether the policy is active or not.
Policy Name: Policy1
Active: yes
Policy... (8 Replies)
version info :
vi availabe with RHEL 5.4
I have a text file with 10,000 lines. I want to copy lines from 5000th line to 7000th and redirect to a file. Any idea how I can do this?
Note:
The above scenario is just an example. In my actual requirement, the file has 14 million lines and I want... (9 Replies)
Hi everyone,
I know the following questions are noobish questions but I am asking them because I am confused about the basics of history behind UNIX and LINUX.
Ok onto business, my questions are-:
Was/Is UNIX ever an open source operating system ?
If UNIX was... (21 Replies)
Hello,
I couldn't find an actual introduction thread, so I decided to just put this here.
I go by d0wngrade online. I have been programming in multiple languages for about 15+ years. I started with standard web design languages like HTML and CSS, but I then advanced from design to development... (2 Replies)
Hi guys...
The first active code line in AudioScope.sh is set -u .
This causes a complete exit if a variable is used/found but has not been allocated at the start of the program.
However, apart from writing code to do the task, is there a switch to to check which variables have been... (17 Replies)
Hi.
In thread https://www.unix.com/shell-programming-and-scripting/267833-grouping-counting.html rovf and I had a mini-discussion on grep and awk.
Here is a demo script that compares the awk and grep approaches for this single problem:
#!/usr/bin/env bash
# @(#) s2 Demonstrate group... (1 Reply)
Hello,
I have to fish out some specific columns from a file based on the header value. I have the list of columns I need in a different file. I thought I could read in the list of headers I need,
# file with header names of required columns in required order
headers_file=$2
# read contents... (11 Replies)
For those interested in installing dash shell on OSX Lion to help test POSIX compliancy of shell scripts, it is quite easy. I did it like this:
If you don't have gcc on your system:
0. Download and install the Command Line Tools for Xcode package from Sign In - Apple *
1. Download the dash... (2 Replies)
Hello and thanks in advance for any help anyone can offer me
I'm trying to learn the find command and thought I was understanding it... Apparently I was wrong. I was doing compound searches and I started getting weird results with the -size test. I was trying to do a search on a 1G file owned by... (14 Replies)
I have data of an excel files as given below,
file1
org1_1 1 1 2.5 100
org1_2 1 2 5.5 98
org1_3 1 3 7.2 88
file2
org2_1 1 1 2.5 100
org2_2 1 2 5.5 56
org2_3 1 3 7.2 70
I have multiple excel files as above shown.
I have to copy column 1, column 4 and paste into a new excel file as... (26 Replies)
Dear All,
Taking a break from Vue.js coding for the site, SEO and YT videos; and hopefully addressing some well deserved criticism from some here that I have been too focused on the visual aspects of the forums versus the substance and the community....
While the "current generation... (9 Replies)
Hi all...
Well guys and gals, I jumped in at the deep end and found things that PERL cannot do by default.
Many tricky terminal escape codes are not catered for so I had to create workarounds.
One thing I searched for was this:
Passing perl variable to shell command
AND, @Neo this was... (15 Replies)