Rockwell Automation 9220-WINTA ControlNet Traffic Analyzer Reference Manual - Manual (Page 50)

Publication 9220-052C-EN-P - August 2002
4-16 Triggers and Filters
Interpreting Control Bits
The bits of the control field are numbered 0 through 7 and are described
below.
Bit 0 - Fixed Tag (type of LPacket)
Bit 0 is the least significant bit of the control field. Bit 0 indicates the type of
LPacket. When set (bit 0 = 1), the LPacket is a fixed tag LPacket. Conversely, when
clear (bit 0 = 0), the LPacket is a generic tag LPacket.
Bit 1 - Tag Pad (Odd Tag Size)
Bit 1 of the control field indicates whether the tag field contains an even or odd
number of bytes. When clear (bit 1 = 0), it indicates that the tag contains an even
number of bytes. When set (bit 1 = 1), it indicates that the tag contains an odd
number of bytes. A fixed LPacket has an even tag so bit 1 = 0 and a generic LPacket
has an odd tag so bit 1 = 1.
Bit 2 - Data Pad (Odd Link Data Size)
Bit 2 of the control field indicates whether the link data contains an even or odd
number of bytes. When clear (bit 2 = 0), it indicates that the link data contains an
even number of bytes. When set (bit 2 = 1), it indicates that the link data contains
an odd number of bytes.
Bit 3 - Reserved
Bit 3 of the control field is reserved.
Bit 4 - Generic Tag (Type of LPacket)
Bit 4 of the control field is the inverse of bit 0 (see bit 0 above). If bit 0 is clear, then
bit 4 will be set. If bit 0 is set, then bit 4 will be clear.
Bit 5, 6, 7 - Reserved 7:5
Bits 5, 6, and 7 of the control field are reserved.