LJM Debug Logger Configs

The LJM debug logger can output debug information to a file.

Relevant Functions

To read the debug logger configurations, use LJM_ReadLibraryConfigStringS.

To write the debug logger configurations, use LJM_WriteLibraryConfigStringS or LJM_LoadConfigurationFile.

For more information, see Debugging Functions.

For more LJM configurations, see Library Configuration Functions.

LJM_DEBUG_LOG_FILE

Default

Windows Vista and later:

C:\ProgramData\LabJack\LJM\ljm.log

Windows XP:

C:\Documents and Settings\All Users\Application Data\LabJack\LJM\ljm.log

Mac OS X and Linux:

/usr/local/share/LabJack/LJM/ljm.log

Summary

LJM_DEBUG_LOG_FILE is a string-based readable-writable LJM library configuration which sets the absolute or relative path of the file to output log messages to.

The constant LJM_DEBUG_LOG_FILE can be used interchangeably with the string "LJM_DEBUG_LOG_FILE".

Details

The configuration value of LJM_DEBUG_LOG_FILE is meaningless if LJM_DEBUG_LOG_MODE is in LJM_DEBUG_LOG_MODE_NEVER (which is the default).

Relevant Constants

See the debug logger parameters, especially LJM_DEBUG_LOG_MODE.

Example

Set LJM to log to the log file "ljm_monday.log"

C

char ErrorString[LJM_MAX_NAME_SIZE];
char DebugLogFile[LJM_MAX_NAME_SIZE];
int LJMError;

printf("Setting LJM_DEBUG_LOG_MODE to LJM_DEBUG_LOG_MODE_CONTINUOUS\n");
LJMError = LJM_WriteLibraryConfigS(LJM_DEBUG_LOG_MODE, LJM_DEBUG_LOG_MODE_CONTINUOUS);
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_WriteLibraryConfigS error: %s\n", ErrorString);
}

printf("Setting LJM_DEBUG_LOG_FILE to ljm_monday.log\n");
LJMError = LJM_WriteLibraryConfigStringS(LJM_DEBUG_LOG_FILE, "ljm_monday.log");
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_WriteLibraryConfigStringS error: %s\n", ErrorString);
}

LJMError = LJM_ReadLibraryConfigStringS(LJM_DEBUG_LOG_FILE, DebugLogFile);
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_ReadLibraryConfigStringS error: %s\n", ErrorString);
}
printf("LJM_DEBUG_LOG_FILE is now %s\n", DebugLogFile);

Possible output:

Setting LJM_DEBUG_LOG_MODE to LJM_DEBUG_LOG_MODE_CONTINUOUS
Setting LJM_DEBUG_LOG_FILE to ljm_monday.log
LJM_DEBUG_LOG_FILE is now ljm_monday.log

LJM_DEBUG_LOG_FILE_MAX_SIZE

LJM_DEBUG_LOG_FILE_MAX_SIZE is a numerical readable-writable LJM library configuration that limits the number of characters in the debug log file. Once the debug log file has exceeded LJM_DEBUG_LOG_FILE_MAX_SIZE characters, it will be reset to 0 characters and debug logging will continue. The largest LJM_DEBUG_LOG_FILE_MAX_SIZE you may use is the largest file size of your operating system. The default is 50000 characters.

The constant LJM_DEBUG_LOG_FILE_MAX_SIZE can be used interchangeably with the string "LJM_DEBUG_LOG_FILE_MAX_SIZE".

Example

Set LJM_DEBUG_LOG_FILE_MAX_SIZE to a larger-than-default size

C

char ErrorString[LJM_MAX_NAME_SIZE];
int LJMError;
LJMError = LJM_WriteLibraryConfigS(LJM_DEBUG_LOG_FILE_MAX_SIZE, 123456789);
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_WriteLibraryConfigS error: %s\n", ErrorString);
}

For more LJM configurations, see Library Configuration Functions.

LJM_DEBUG_LOG_LEVEL

LJM_DEBUG_LOG_LEVEL is a numerical readable-writable LJM library configuration with the following options:

LJM_STREAM_PACKET = 1
LJM_TRACE = 2
LJM_DEBUG = 4
LJM_INFO = 6
LJM_PACKET = 7
LJM_WARNING = 8
LJM_USER = 9
LJM_ERROR = 10
LJM_FATAL = 12

The constant LJM_DEBUG_LOG_LEVEL can be used interchangeably with the string "LJM_DEBUG_LOG_LEVEL".

Details

LJM_DEBUG_LOG_MODE must allow for logging in order for LJM_DEBUG_LOG_LEVEL to have any effect.

LJM_DEBUG_LOG_LEVEL determines which log messages are output. LJM outputs the debug messages that are of the current LJM_DEBUG_LOG_LEVEL and greater.

Example

Read LJM_DEBUG_LOG_LEVEL then set LJM_DEBUG_LOG_LEVEL to LJM_WARNING

C

char ErrorString[LJM_MAX_NAME_SIZE];
double value;

int LJMError = LJM_ReadLibraryConfigS(LJM_DEBUG_LOG_LEVEL, &value);
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_ReadLibraryConfigS error: %s\n", ErrorString);
}
printf("The default for LJM_DEBUG_LOG_LEVEL is %.00f\n", value);

value = LJM_WARNING;
printf("Setting LJM_DEBUG_LOG_LEVEL to %.00f\n", value);
LJMError = LJM_WriteLibraryConfigS(LJM_DEBUG_LOG_LEVEL, value);
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_DEBUG_LOG_LEVEL error: %s\n", ErrorString);
}

Possible output:

The default for LJM_DEBUG_LOG_LEVEL is 7
Setting LJM_DEBUG_LOG_LEVEL to 8

LJM_DEBUG_LOG_MODE

LJM_DEBUG_LOG_MODE is a numerical readable-writable LJM library configuration with the following options:

LJM_DEBUG_LOG_MODE_NEVER = 1

LJM will never log messages
The log thread will never start

LJM_DEBUG_LOG_MODE_CONTINUOUS = 2

LJM will log all messages with priority equal to or greater than the current LJM_DEBUG_LOG_LEVEL
The log thread will start when the first message with priority equal to or greater than the current LJM_DEBUG_LOG_LEVEL is scheduled to be output

LJM_DEBUG_LOG_MODE_ON_ERROR = 3

LJM will collect all messages with priority equal to or greater than the current LJM_DEBUG_LOG_LEVEL, but only output those messages if a log message with priority equal to or greater than LJM_ERROR (10) is scheduled to be output
The maximum number of messages that will be collected is LJM_DEBUG_LOG_BUFFER_MAX_SIZE
The log thread will start when the first message with priority equal to or greater than the current LJM_DEBUG_LOG_LEVEL is scheduled to be output

The constant LJM_DEBUG_LOG_MODE can be used interchangeably with the string "LJM_DEBUG_LOG_MODE".

Example

Read LJM_DEBUG_LOG_MODE, set LJM_DEBUG_LOG_MODE, then read it again

C

char ErrorString[LJM_MAX_NAME_SIZE];
double Value = 0;
int LJMError = LJM_ReadLibraryConfigS(LJM_DEBUG_LOG_MODE, &Value);
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_ReadLibraryConfigS error: %s\n", ErrorString);
}
printf("The default for LJM_DEBUG_LOG_MODE is %.00f\n", Value);

Value = LJM_DEBUG_LOG_MODE_CONTINUOUS;
printf("Setting LJM_DEBUG_LOG_MODE to %.00f\n", Value);
LJMError = LJM_WriteLibraryConfigS(LJM_DEBUG_LOG_MODE, Value);
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_WriteLibraryConfigS error: %s\n", ErrorString);
}

LJMError = LJM_ReadLibraryConfigS(LJM_DEBUG_LOG_MODE, &Value);
if (LJMError != 0) {
    LJM_ErrorToString(LJMError, ErrorString);
    printf("LJM_ReadLibraryConfigS error: %s\n", ErrorString);
}
printf("LJM_DEBUG_LOG_MODE is now %.00f\n", Value);

Possible output:

The default for LJM_DEBUG_LOG_MODE is 1
Setting LJM_DEBUG_LOG_MODE to 2
LJM_DEBUG_LOG_MODE is now 2

LJM_DEBUG_LOG_BUFFER_MAX_SIZE

LJM_DEBUG_LOG_BUFFER_MAX_SIZE is a numerical readable-writeable LJM library configuration that sets how many messages the log buffer can hold.

Default Value: 4000

LJM_DEBUG_LOG_SLEEP_TIME_MS

LJM_DEBUG_LOG_SLEEP_TIME_MS is a numerical readable-writeable LJM Library configuration that sets how often the logger thread will run.

Default Value: 20