Process Data Info and Configuration
Description
Process data information and configuration offers various possibilities related to process data:
Selection of a process dataset specified by the device
Information about the structure of the input and output data
Information about the last valid value for input and output data
As a diagnosis function, monitoring of the updates of certain process values is available. If these are not updated in the specified time, the device sends corresponding diagnosis messages.
Invalid Process Data
Input data (from the device to the master) is only marked as invalid if the device has the Failure device status.
Info
In the case of individual pieces of faulty data, the data is not marked as invalid but is instead replaced by substitution values or error codes. This is to be taken into account during the evaluation.
ISDU
PD Profile Selection
There is only one PD Profile available.
PD Description
This parameter is used to specify the structure of the currently selected process data profile for input and output data. The individual process data variables are described.
The total list is accessible via subindex 0, a single entry is possible using a specific subindex. Subindex 1 corresponds to the least significant (or the element most recently transferred in the process data stream). When reading out the entire list, this element is transferred first.
The length of the list is dependent on which process data profile is selected. A single element has a length of 3 bytes.
Last Valid Process Data
This parameter indicates the most recently valid input or output data of the device. The first transferred byte in the process data (MSB) is transferred first. This is an exact representation. Access occurs via subindex 0.
Events
PD Update Timeout
Is this event supported
With special process data values, the device automatically checks whether the values are updated in the time period specified by the device. If an update timeout is triggered as a result, this is output via the following diagnosis messages:
Event Code |
Event Type |
Event – Description – Remedy |
Device Status |
|---|---|---|---|
0x1851 (6225) |
Notification |
Process Data Update Timeout – for information purposes only. A PDinput has been delayed over an extended period of time. |
0 – Device is operating properly. |
0x1852 (6226) |
Warning |
Multiple Process Data Update Timeout – for information purposes only. A PDinput has been delayed over an extended period of time. |
0 – Device is operating properly. |
PD Invalid
PD Inputs Invalid:
Input data (device-to-master) is marked as invalid if the device status (see section Device status and detailed device status) of the device is Failure. In all other states, replacement values for the data are output for which the content cannot be output correctly.