Copyright © 2015 epsilonRT, All rights reserved.
mbpoll is a command line utility to communicate with ModBus slave (RTU or TCP).
It uses libmodbus.
This is a multiplatform project, the compilation was tested on GNU Linux
x86 and x86_64, Microsoft Windows 7 x86 and GNU Linux ARM 6 (Raspbian).
Although the syntax of these options is very close modpoll proconX program,
it is a completely independent project.
mbpoll can:
- read discrete inputs
- read and write binary outputs (coil)
- read input registers
- read and write output registers (holding register)
The reading and writing registers may be in decimal, hexadecimal or floating single precision.
The installation instructions are in the INSTALL file.
For example, for a debian system:
-
Install dependencies:
sudo apt-get update sudo apt-get install cmake build-essential -
Generate Makefile with cmake:
cd mbpoll mkdir build cd build cmake .. -
Compile and install mbpoll:
make sudo make install
If you prefer, you can in the place of direct compilation create a package and install it:
make package
sudo dpkg -i * .deb
That's all !
The following command is used to read the input registers 1 and 2 of the slave at address 33 connected through RTU /dev/ttyUSB2 (38400 Bd)
mbpoll -a 33 -b 38400 -t 3 -r 1 -c 2 /dev/ttyUSB2
mbpoll 0.1-10 - FieldTalk(tm) Modbus(R) Master Simulator
Copyright (c) 2015 epsilonRT, All rights reserved.
This software is governed by the CeCILL license <http://www.cecill.info>
Protocol configuration: Modbus RTU
Slave configuration...: address = [33]
start reference = 1, count = 2
Communication.........: /dev/ttyUSB2, 38400-8E1
t/o 1.00 s, poll rate 1000 ms
Data type.............: 16-bit register, input register table
-- Polling slave 33... Ctrl-C to stop)
[1]: 9997
[2]: 10034
-- Polling slave 33... Ctrl-C to stop)
[1]: 10007
[2]: 10034
-- Polling slave 33... Ctrl-C to stop)
[1]: 10007
[2]: 10034
-- Polling slave 33... Ctrl-C to stop)
[1]: 10007
[2]: 10034
^C--- /dev/ttyUSB2 poll statistics ---
4 frames transmitted, 4 received, 0 errors, 0.0% frame loss
everything was closed.
Have a nice day !
A complete help is available with the -h option:
usage : mbpoll [ options ] device|host [ writevalues... ] [ options ]
ModBus Master Simulator. It allows to read and write in ModBus slave registers
connected by serial (RTU only) or TCP.
Arguments :
device Serial port when using ModBus RTU protocol
COM1, COM2 ... on Windows
/dev/ttyS0, /dev/ttyS1 ... on Linux
/dev/ser1, /dev/ser2 ... on QNX
host Host name or dotted IP address when using ModBus/TCP protocol
writevalues List of values to be written.
If none specified (default) mbpoll reads data.
If negative numbers are provided, it will precede the list of
data to be written by two dashes ('--'). for example :
mbpoll -t4:int /dev/ttyUSB0 -- 123 -1568 8974 -12
General options :
-m # mode (rtu or tcp, TCP is default)
-a # Slave address (1-255 for rtu, 0-255 for tcp, 1 is default)
for reading, it is possible to give an address list
separated by commas or colons, for example :
-a 32,33,34,36:40 read [32,33,34,36,37,38,39,40]
-r # Start reference (1 is default)
-c # Number of values to read (1-125, 1 is default)
-u Read the description of the type, the current status, and other
information specific to a remote device (RTU only)
-t 0 Discrete output (coil) data type (binary 0 or 1)
-t 1 Discrete input data type (binary 0 or 1)
-t 3 16-bit input register data type
-t 3:hex 16-bit input register data type with hex display
-t 3:int 32-bit integer data type in input register table
-t 3:float 32-bit float data type in input register table
-t 4 16-bit output (holding) register data type (default)
-t 4:hex 16-bit output (holding) register data type with hex display
-t 4:int 32-bit integer data type in output (holding) register table
-t 4:float 32-bit float data type in output (holding) register table
-0 First reference is 0 (PDU addressing) instead 1
-1 Poll only once only, otherwise every poll rate interval
-l # Poll rate in ms, ( > 100, 1000 is default)
-o # Time-out in seconds (0.01 - 10.00, 1.00 s is default)
Options for ModBus / TCP :
-p # TCP port number (502 is default)
Options for ModBus RTU :
-b # Baudrate (1200-921600, 19200 is default)
-d # Databits (7 or 8, 8 for RTU)
-s # Stopbits (1 or 2, 1 is default)
-P # Parity (none, even, odd, even is default)
-4 RS-485 mode
-h Print this help summary page
-V Print version and exit
-v Verbose mode. Causes mbpoll to print debugging messages about
its progress. This is helpful in debugging connection...
This software is governed by the CeCILL license under French law and abiding by the rules of distribution of free software. You can use, modify and/ or redistribute the software under the terms of the CeCILL license as circulated by CEA, CNRS and INRIA at the following URL "http://www.cecill.info".
As a counterpart to the access to the source code and rights to copy, modify and redistribute granted by the license, users are provided only with a limited warranty and the software's author, the holder of the economic rights, and the successive licensors have only limited liability.
In this respect, the user's attention is drawn to the risks associated with loading, using, modifying and/or developing or reproducing the software by the user in light of its specific status of free software, that may mean that it is complicated to manipulate, and that also therefore means that it is reserved for developers and experienced professionals having in-depth computer knowledge. Users are therefore encouraged to load and test the software's suitability as regards their requirements in conditions enabling the security of their systems and/or data to be ensured and, more generally, to use and operate it in the same conditions as regards security.
The fact that you are presently reading this means that you have had knowledge of the CeCILL license and that you accept its terms.