X90 mobile modules
216
X90 mobile system User's manual V 1.20 - Translation of the original manual
Flatstream mode
Name:
FlatstreamMode
In the input direction, the transmit array is generated automatically. This register offers 2 options to the user that
allow an incoming data stream to have a more compact arrangement. Once enabled, the program code for eval-
uation must be adapted accordingly.
Information:
All B&R modules that offer Flatstream mode support options "Large segments" and "MultiSegmentM-
TUs" in the output direction. Compact transfer must be explicitly allowed only in the input direction.
Bit structure:
Bit
Description
Value
Information
0
Not allowed (default)
0
MultiSegmentMTU
1
Permitted
0
Not allowed (default)
1
Large segments
1
Permitted
2 - 7
Reserved
Standard
By default, both options relating to compact transfer in the input direction are disabled.
1. The module only forms segments that are at least one byte smaller than the enabled MTU. Each sequence
begins with a control byte so that the data stream is clearly structured and relatively easy to evaluate.
2. Since a Flatstream message is permitted to be any length, the last segment of the message frequently does
not fill up all of the MTU's space. By default, the remaining bytes during this type of transfer cycle are not used.
Bus cycle 1
Control byte with MessageEndBit = 0
Bus cycle 2
Bus cycle 3
-
-
-
ME1
C
ME1
C
ME0
C
ME1
C
Control byte with MessageEndBit = 1
Segment 1
Segment 2
Segment 3
Message 1
Message 2
ME0
C
Figure 51: Message arrangement in the MTU (default)