Allen-Bradley 1444-TSCX02-02RB User Manual page 408

Appendix A CIP Objects
408
Table 137 - Event Log Entries (continued)
4 SessionInstance
5 Reserved
6 Pad
8 PacketCountDown DWORD
The Dynamix 1444 return the following as part of an 0x4B service response.
Table 138 - 0x4B Service Responses
Byte Offset Structure
Within Member
Structure
0 SessionInstance
1 Reserved
2 Completed Records UINT
4 RecordSize
8 PacketCountDown
12 Status
16 Data Array
Rockwell Automation Publication 1444-UM001D-EN-P - June 2018
USINT The SessionInstance is initially specified as 0, but on subsequent
calls the SessionInstance returned in the response must be passed
here.
BYTE
INT Used to align data to a 32-bit boundary.
The PacketCountDown is initially specified as 0, but on subsequent
calls the PacketCountDown returned in the response must be
passed here.
Data Description
Type
USINT The host copies the SessionInstance returned here into each
subsequent Record Request. Up to 3 instances are supported.
USINT
Incremented each time that another complete record has been
transferred.
There are often several packets per completed record.
UDINT In this case, it is fixed at the size of one event log record, 16
bytes.
DWORD The host copies the PacketCountDown returned here into each
subsequent Record Request. When the PacketCountDown
reaches 0, the session is complete and the final value in
CompletedRecords is all that is transferred.
DINT Any of the following can be returned:
• eUnrecognizedSession (1)
• e maxSessionsReached (2)
• ePacketCountOutOfSequence (3)
• eInvalidBufferSelect(4)
• eNoDataAvailable (5)
• eGeneralError (6)
For all successful requests eSUCCESS (0) is returned, any other
value ends the session.
DWORD Each record is an array of DWORDs of size RecordSize. This array
[50] of records can be large. It is the responsibility of the calling
application to handle these records appropriately. The DWORD
type is just a placeholder for the actual types in the data
structure that maps to this RecordArray. See the next section for
details.