1.2.9. Files on the Target System

Which files are necessary or created on your target file system, hardly depends on the type of runtime and the extended which you are using. At the absolute minimum, you will use an embedded runtime system, with a static configuration, no extended features and a flash file system for your boot projects. So you won’t need any file system at all. But contrary to this, the following chapter will describe a full runtime system with all features.

1.2.9.1. Boot projects

By default, boot projects are saved as files, named <application>.app on the target file system. On embedded runtime systems they can be also saved in flash with the runtime component SysFileFlash.

If we are using a target file system, the runtime system will generate the following two files when a boot project is created:

• <application>.app

  This file contains the application code and data.
• <application>.crc

  This file contains a CRC value of <application>.app which is verified at boot time.

With the setting [CmpApp]->RetainType.Applications=OnPowerfail, the target will save the “retain” and “retain persistent” data to the file system. For this to work, the target needs to be shut down correctly. On power fail, this can be done with a big enough condensator, which can buffer the target long enough to shut it down. In this case the following file is generated for every application on shutdown:

• <application>.ret

  This file contains the complete retain data segment of the corresponding application, and is therefore as big as the retain-segment is configured in the corresponding device description.

1.2.9.2. I/O manager

The I/O manager forwards all configuration-, read- and write-requests to the attached device drivers. Please refer to chapter 7 for a more detailed description.

Every Parameter which is set in the I/O Configuration is saved to the file “IoConfig.par”. Those values are then restored at the next power up from this file.

1.2.9.3. User management

The User management of the CODESYS Runtime encapsulates the whole rights- and user management into the component CmpUserDB. This component can be implemented by the OEM customer himself to match his special requirements. But there is also a fully complete user database included in the runtime.

This uUser database saves it’s user and rights tables in simple CSV files on the target file system:

• UserMgmtDB.csv

  This file contains all users and groups, which are downloaded by the CODESYS programming system.
• UserMgmtRightsDB.csv

  The content of this file is downloaded from the CODESYS programming system, too.

  It contains all configured user rights for the different files and devices.

1.2.9.4. Visualization

If the target visualization is running in a different process as the runtime system, it needs a way to exchange the bitmap pool between the two processes. The bitmap pool consists of IDs, associated with image file names on the file system. This means, that when you are using a target visualization with images on your target, you will get also the following file, beside all the necessary image files:

• IPCBitmapPool.cfg

  This file is used to share an image pool between the two processes of the target visualization and the soft PLC.