82 - Configuring the DeviceMaster in TIA Portal
DeviceMaster PNIO | UP User Guide
: 2000639 Rev. A
Configuring the DeviceMaster in TIA Portal
on Page 95 for more information regarding oversize
packets handling and the method to retrieve an entire oversize packet without
losing data.
This table shows the data format of an output submodule.
The output data has the same format as the input data of an input submodule.
The DeviceMaster transmits the number of output data indicated by the length
field when the sequence number field changes. The gateway only transmits the
output data once. No further data is transmitted until the sequence number is
changed again.
An output submodule also has a 2-byte input data, as shown in following table.
This 16-bit integer is the sequence number of the last output data packet that was
transmitted. If you want to confirm that the last data written to the output data
area has been transmitted, compare the sequence number of the transmitted
output data with the input data of that submodule. If they are the same, the data
has been transmitted successfully.
Byte Offset
Output Submodule
Data Type
Description
0-1
WORD
Sequence Number (Big endian)
2-3
WORD
Data Length (Big endian)
4..N
Array of BYTE
Data Array (Maximum 220 bytes)
Byte Offset Data Type
Description
0-1
WORD
Last Transmitted Sequence Number (Big endian)