FBWF side effects

With the FBWF there may be side effects where the protection of the respective medium is no longer guaranteed.

The standard configuration of the FBWF is set to protect the system medium that is HardDiskVolume1. So that a volume is recognized as HardDiskVolume1, the respective medium is either connected solely to the primary IDE-bus or connected to the system as the primary master. The FBWF must be reconfigured if none of these requirements is met.

Sample configuration:

A C69xx with hard disk and Compact Flash card, the system being located on the Compact Flash card.

If the computer starts without a hard disk connected, the system is on HardDiskVolume1. However, if the computer is started with a hard disk connected, the system will be HardDiskVolume2. The reason for this is that the hard disk is recognized as the primary master and the Compact Flash card as the secondary master.

The FBWF must be reconfigured in order to eliminate this side effect:

• The drive is removed from the configuration with fbwfmgr /removevolume C: 1.
• Next, the new drive (system) can be added to the configuration fbwfmgr /addvolume D:

Following a restart, add the standard releases to the configuration again (C:\Data and C:\TwinCAT\Boot).

Summary:

• Standard C69xx:
  The CF card is \Device\HarddiskVolume1 with the drive letter C:
• Extension by a hard disk:
  The CF card is \Device\HarddiskVolume2 with the drive letter C:
  The hard disk is \Device\HarddiskVolume1 with the drive letter D:

The EWF (Enhanced Write Filter) is not affected by this side effect.