02. Log

The log object is a built-in extension object that provides logging output functionality.

Functional overview:

• Able to set output level of the system log.
• Able to set log output destination.
• Able to output arbitrary log messages from the operation script.
• Able to get memory usage information on the operation script.

Limitations:

• The maximum storage capacity of the non-volatile memory for logs is 366KB.
  When full, the old log is overwritten.

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log Global Object

Methods()/Properties	Summary	Version	Note
log.setLevel()	Sets the level and the output destination of the system log.
log.clear()	Clears logs stored in non-volatile memory.
log.getStoredSize()	Gets the size of the currently saved log.
log.getStorageSize()	Gets the storage size available for logs.
log.printLevel()	Sets the output destination of the print() function.
print()	Prints the log message.		This is a globally scoped function.
heap()	Gets the memory usage information on the operation script.	02.03.00+	This is a globally scoped function.

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Details

log.setLevel([level[,output[,instance]]])

Sets the level and the output destination of the system log.
The last set value is saved in non-volatile memory.
Therefore, it is possible to simply leave the system log disabled. This method is used to investigate potential causes when unexpected behaviors occur.

Name	Type	M/O	Summary	Note
level	number	optional	Log level setting -1: Disabled 0: Error level 1: Warning level 2: Debug level 3: Trace level The default value is -1.
output	number	optional	Output destination setting 0: All disabled 1: Saves the log to the non-volatile memory on the NEQTO device 2: Outputs the log from the serial port of NEQTO device 3: Enable 1 and 2 4: Sends the log to NEQTO Console in real time 5: Enable 1 and 4 6: Enable 2 and 4 7: Enable 1, 2 and 4 The default value is 0.	Version 01.00.01+ 4 or above: Version 01.03.00+ The "Send log to NEQTO Console in real time" function should be used for debugging purposes only. Since this function uses many communication resources, it may increase the processing load on the device and cause data transmission delays. In addition, as there are no retransmission processes in cases of communication failures, it may result in lost log data.
instance	number	optional, mandatory	Specify the instance ID to which the real-time log will be sent on the NEQTO Console. For the available range of instance IDs, refer here.	Version 01.03.00+ It is mandatory only if 'output' is 4 or above. Real-time logs will be sent to the NEQTO Console using the following MQTT specification: Item Setting value Object ID Addressable Text Display (Fixed) Instance ID Any Resource ID Text (Fixed)
return	undefined	-	-	When an error occurs, an exception is raised.

log.clear()

Clears the logs stored in non-volatile memory.

Name	Type	M/O	Summary	Note
return	undefined	-	-

log.getStoredSize()

Gets the size of the currently saved log.

Name	Type	M/O	Summary	Note
return	number	-	Log size currently saved [byte].

log.getStorageSize()

Gets the amount of storage available to save logs.

Name	Type	M/O	Summary	Note
return	number	-	Log size that can be saved [byte].

log.printLevel([output[,instance]])

Sets the output destination of the print() function.
This print level is always initialized with default values at the start of script execution.

Name	Type	M/O	Summary	Note
output	number	optional	Output destination setting 0: All disabled 1: Saves the log to the non-volatile memory on the NEQTO device 2: Outputs the log from the serial port of NEQTO device 3: Enable 1 and 2 4: Sends the log to NEQTO Console in real time 5: Enable 1 and 4 6: Enable 2 and 4 7: Enable 1, 2 and 4 The default value is 0. After version 01.00.01, the default value is 2 when started in User Console mode.	4 or above: Version 01.03.00+ The "Send log to NEQTO Console in real time" function should be used for debugging purposes only. Since this function uses many communication resources, it may increase the processing load on the device and cause data transmission delays. In addition, as there are no retransmission processes in cases of communication failures, it may result in lost log data.
instance	number	optional, mandatory	Specify the instance ID to which the real-time log will be sent on the NEQTO Console. For the available range of instance IDs, refer here.	Version 01.03.00+ It is mandatory only if 'output' is 4 or above. Real-time logs will be sent to the NEQTO Console using the following MQTT specification: Item Setting value Object ID Addressable Text Display (Fixed) Instance ID Any Resource ID Text (Fixed)
return	undefined	-	-	When an error occurs, an exception is raised.

print(logMsg)

Prints the log message.

Name	Type	M/O	Summary	Note
logMsg	string	mandatory	Message to output as log.
return	undefined	-	-	When an error occurs, an exception is raised.

heap()

Gets the memory usage information on the operation script.

Name	Type	M/O	Summary	Note
return	{HeapInfo}	-	{HeapInfo} : Memory usage information on the operation script

{HeapInfo}

Name	Type	Summary	Note
.total	number	Available memory size [Byte]
.current	number	Current usage memory size [Byte]
.peak	number	Maximum memory usage size to date [Byte]

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Object Usage Examples

Sample 1

This is a sample that outputs the system log and print log from the serial port of NEQTO device.

log.setLevel(0,2);
log.printLevel(2);

Sample 2

This is a sample that sends the system log and print log to NEQTO Console in real time.
The instance ID is an arbitrary value. It is also possible to use the same ID for the system log and the print log.
Available from FW version 01.03.00 or later.

log.setLevel(0,4,1);
log.printLevel(4,2);
//log.printLevel(4,1); /*Available*/

Sample 3

This is a sample that displays memory usage information.

var mem = heap();
print(JSON.stringify(mem));
print(`total: ${mem.total}, current: ${mem.current}, peak: ${mem.peak}`);
print(`usage: ${(mem.current/mem.total*100).toFixed(2)}%, max: ${(mem.peak/mem.total*100).toFixed(2)}%`);

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Updated: 2025-01-28