Enable Alarm For Oversize Packets - Comtrol DeviceMaster PNIO 2000 Series User Manual

Advanced Functions
Enable Alarm for
Oversize Packets
98 - Advanced Functions
For normal input data received during IO update cycles, we use the same InputBuf
structure (Page 90) and the DPRD_DAT instruction to store them in a data block.
Besides, a RecordData structure is defined in the same data block and is used as
the target range of RDREC instruction, as shown in the figure below. The
RecordData structure can hold up to 64 bytes of input data plus the sequence
number and length.
The tag LastRxSeqNum contains the sequence number of the last packet received
on that port. Compare LastRxSeqNum with the sequence number of current packet
Data_block_1.InputBuf.SeqNum, if they are not equal and the packet length
Data_block_1.InputBuf.Length is also larger than the input size (32), then the tag
StartRecDataRd is set, which starts the RDREC instruction.
In this example, up to 64 bytes of a saved packet will be read and stored in
Data_block_1.RecordData. Once the RDREC instruction completes, the
StartRecDataRd tag is cleared.
The DeviceMaster can also notify the IO controller through an alarm when an
oversize packet is available. The feature is disabled by default. Use this procedure
to enable the alarm.
1. Open the web page and click Network | PROFINET IO.
2. Check the Enable channel-specific diagnostics and click the Save button.
Once enabled, the DeviceMaster sends a diagnostic alarm to the IO controller
when an oversize packet is saved. The alarm is a channel-specific diagnostic alarm
with an error type 4096 (16#1000). Using the slot information associated with the
alarm, the IO controller can start a record data read instruction to retrieve the
saved packet for a certain port/device. After the packet is read, the DeviceMaster
clears the alarm automatically.
DeviceMaster PNIO | UP User Guide: 2000639 Rev. A