You can select whether you want your schedules to run as foreground or background tasks. When you create a new schedule, the default is for it to run in the foreground. To run a schedule in the foreground, the iFIX WorkSpace must be running in the run-time environment. Running a schedule in the foreground is useful for testing and debugging VBA scripts.
To run a schedule in the background, the FixBackgroundServer task must be running. If the FixBackgroundServer task is not running, it is automatically started when a schedule is added to the background task. To create a schedule that runs in the background you must change the default setting in the Scheduler Properties dialog box, which is available by right-clicking a schedule and selecting Scheduler Properties from the pop-up menu. You can use this dialog box to change the default setting for a new schedule or for an existing schedule that is set to run in the foreground. Also, you can select whether you want a schedule to run in the foreground or the background, set the window properties, and set the statistics refresh rates.
NOTE: An unsigned write occurs when a database tag is configured for electronic signature, but you write a value directly to that tag without capturing a signature. If you are working in a secure environment with the Electronic Signature option enabled, you must be aware of the impact of unsigned writes to the process database. Unsigned writes can originate from schedules. Refer to the Implications of Database Writes With Electronic Signature section of the Using Electronic Signatures manual for detailed information.
To avoid the possibility of these messages occurring, append the intErrorMode parameter, set to "2", to the schedule's script command. This will send an error message without a prompt to configured iFIX alarm destinations, and the schedule will continue without the need for user intervention.
For example, if the schedule script is as follows:
WriteValue "33", "Fix32.ROXIE.AI_TAG.F_CV"
modify it to:
WriteValue "33", "Fix32.ROXIE.AI_TAG.F_CV", 2
