Freeze

The master device can use the Freeze command in the GlobalControl request telegram, which is a broadcast telegram, to synchronize the reading of the inputs of several slave devices. The slave device acknowledges a Freeze command in the diagnostic data. A DP slave device starts the Freeze mode when it receives a Freeze control command from its assigned DP master device.

In Freeze mode, the inputs of all addressed DP slave devices are frozen to the current value. The input data is not updated again until the DP master device has sent the next Freeze control command to the affected devices. A DP slave device terminates the Freeze mode when it receives an Unfreeze control command from its assigned DP master device.