See T7 and Digit Software to download the LJM Library and LabJack applications.
See the LJM Support page to download minor updates.
- Cross platform
- Supported in multiple languages
- Completely Free
- Well-documented User's Guide
- Device discovery
- Modbus Name-To-Address interpretation - ability to interpret LabJack register names such as "AIN0"
- Error-To-String Interpretation
- Robust debugging interface
- Utility functions to:
- Convert bytes to values
- Perform thermocouple calculations
- Convert IP and MAC numbers
- Versatile Library configurations
- Threaded data streaming and buffering
Support for Windows, Mac OS X, and Linux allows for the same code to be run on different operating systems with the same results, whether it's on your Windows desktop, MacBook laptop, or Raspberry Pi running a distribution of Linux.
Supported In Multiple Languages
Written in C++ with a C API, LabJack maintains and supports wrappers for many programing languages.
#include "LabJackM.h" ... int error, handle; double voltage; error = LJM_OpenS("T7", "USB", "ANY", &handle); // Read the voltage on AIN0 error = LJM_eReadName(handle, "AIN0", &voltage); ...
For more LJM C/C++ code, see the C/C++ Examples page.
from labjack import ljm handle = ljm.openS("T7", "USB", "ANY") # Read the voltage on AIN0 voltage = ljm.eReadName(handle, "AIN0")
For more LJM Python code, see the Python Examples page.
ljmAsm = NET.addAssembly('LabJack.LJM'); ... [ljmError, handle] = LabJack.LJM.OpenS('T7', 'USB', 'ANY', handle); % Read the voltage on AIN0 [ljmError, voltage] = LabJack.LJM.eReadName(handle, 'AIN0', 0); ...
For more LJM MATLAB code, see the MATLAB Examples page.
using LabJack; ... int handle; LJM.OpenS("T7", "USB", "ANY", ref handle); // Read the voltage on AIN0 double voltage; LJM.eReadName(handle, "AIN0", ref voltage); ...
For more LJM C# .NET code, see the C# .NET Examples page.
Some other supported languages:
LJM's API allows for easy integration into most languages. If the language you use isn't currently supported, feel free to contact us for assistance in integrating LJM into your project.
LJM Is For Any Level Of Expertise
You don't need to be familiar with Modbus to use LJM. Simply use LJM's Easy Functions for direct access to all the features your LabJack device provides.
If you do prefer to use Modbus, LJM's Raw Byte Functions provide byte-level control to manually send and receive Modbus packets.
Using LJM's name-to-address map, you can communicate with LabJack devices using the readable names of data values, such as "AIN0", "AIN0_RANGE", "ETHERNET_IP", or "WIFI_STATUS".
LJM provides functions that convert readable Modbus register names to a register addresses, such as LJM_NameToAddress. Or, you can directly interact with your LabJack device using the Name-style Easy functions. (Although you can use the Address-style Easy functions if you prefer.)
You can easily look up Modbus registers on the Modbus Map page.
Easy Device Connection
Connecting to a LabJack device is simple. Here's some ways you can connect:
|Just want to open any LabJack device?||Open a connection to the
first found LabJack device.
|Just want to connect to any device
on the network or on a USB hub?
|Filter based on connection type.|
|Just want to open any LabJack Digit or T7?||Filter based on device type.|
|Got a network with static IP address?||Open by IP address.|
|Got a T7 on a DHCP network or on a large USB hub?||Open by serial number.|
Don't want to mess with serial numbers or IP addresses,
|Open by customizable name.|
Using the LJM_ErrorToString function, LJM converts error codes to near-English. Here's some examples of errors and their output from LJM:
- 1227 means "LJME_DEVICE_NOT_FOUND"
- 2420 means "DEVICE_NAME_MUST_BE_ALPHANUM"
LJM's activity log file allows you to see what's going on inside LJM. LJM's Debug Logger output includes data packets, trace information, warnings, and errors. Here's some of the features the Debug Logger sports:
- Configurable logger priority/verbosity level
- Log to an arbitrary file location
- Set the log file maximum size
- Add user-code debug information in-line to the activity log file with the Debug Logger system using the LJM_Log function
For applications with limited processing power, LJM can log messages according to your particular processing constraints. Set the logger mode to:
- Never log (default)
- Log continuously
- Collect log messages and only output them when an error occurs
Customize the behavior of the LJM library to fit your needs. See the full list of Configuration Parameters.
You can also put a configuration file on your system and load it into LJM, so that one configuration that works well can be loaded for multiple programs. (It's also easy to edit!)
Don't hesitate to ask:
We have used your products very successfully through the years.—Duane V., Boeing