Customization

TcLog is design to be easily customizable. This page shows how to customize the logger to your needs.

Custom logging templates

If one wants to record sensor data instead of the standard logs, for example, this is possible. The easiest way to do this is to program a wrapper around TcLog that enforces the specific template.

Example: Logging of sensor data

Suppose we want to record sensor data in REAL format. The data is to be saved in a csv file that has the following format:

hh:mm:ss;device designation;value;unit

And the output should look like this:

10:33:15;+CC1-B31;35.1;°C

Wrapper around TcLog

As wrapper we use an function block that encapsulates TcLog and enforces the data input with the help of the inputs. Furthermore it implements the interface ILog which establishes the link between logger and base logger.

FUNCTION_BLOCK UserLog IMPLEMENTS ILog
VAR_INPUT
  Condition: BOOL;
  Identification: STRING;
  Value: REAL;
  Unit: STRING;
END_VAR
VAR
  _getTimeData: DateTime;
  _timestamp: STRING;
END_VAR
VAR_STAT
  _logger: TcLog; 
END_VAR

_getTimeData();
_timestamp := _getTimeData.ToString('hh:mm:ss');

_logger
  .OnCondition(Condition)
  .AppendString(_timestamp)
  .AppendString(';')
  .AppendString(Identification)
  .AppendString(';')
  .AppendAny(Value)
  .AppendString(';')
  .AppendString(Unit)
  .ToCustomFormat('');

We can use the helper function GenerateTimeData, which returns the current date and time formatted via the .ToString(Format) method. With its help we generate the timestamp of the sensor data.

The .ToCustomFormat('') method at the end of the chain causes the message to be logged unchanged. No additional information like further timestamps or instance path will be appended.

The interface ILog

The interface is implemented by passing the logger reference to the TcLog instance:

METHOD SetLogger : BOOL
VAR_INPUT
  ref2Core : REFERENCE TO TcLogCore;
END_VAR

_logger.SetLogger(ref2Core);

Calling the wrapper

Somewhere in our program TcLogCore is called cyclically. If there is more than one instance of it, we can tell our logger which instance we want via .SetLogger(Instance). Otherwise the configuration of the logger singleton is used.

VAR
  _newLogger: TcLogCore;
  _rTrigLog : R_TRIG;
  _log : BOOL;
  _myLog : UserLog;
  _myValue: REAL := 1.0;
  _myValue2: REAL := 2.0;
END_VAR

_newLogger
  .MinimumLevel(LogLevels.Information)
  .SetRollingInterval(RollingIntervals.Hourly)
  .WriteToFile('c:\logs\', 'sensor.csv')
  .DeleteLogFilesAfterDays(1)
  .RunLogger();
  
_myLog.SetLogger(_newLogger);
_rTrigLog(CLK := _log);

_myLog(
  Condition := _rTrigLog.Q,
    Identification := '+CC1-B31',
  Value := _myValue,
  Unit := '°C');
  
_myLog(
  Condition := _rTrigLog.Q,
  Identification := '+CC1-B32',
  Value := _myValue2,
  Unit := '°C');

As soon as logging is triggered via _log, the csv file and the entries in it are created:

Custom logging

Use of custom loggers

TcLogCore implements the ILogCore interface which defines the LogCustomFormat and LogStandardFormat methods. A custom logger with for example other log sinks can be created in two ways:

  1. create a new FB that inherits from TcLogCore. Thereby the new FB can be extended by additional functions and at the same time brings along all methods that TcLogCore has.
  2. create a new FB that implements the ILogCore interface. This way the logger can be rewritten from scratch. The interface ensures that the existing instances of TcLog in the code can still be used.