X90 mobile modules
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X90 mobile system User's manual V 1.20 - Translation of the original manual
Configuration
The Forward function must only be enabled for the input direction. 2 additional configuration registers are available
for doing so. Flatstream modules have been optimized in such a way that they support this function. In the output
direction, the Forward function can be used as soon as the size of OutputMTU is specified.
Number of unacknowledged sequences
Name:
Forward
With register "Forward", the user specifies how many unacknowledged sequences the module is permitted to
transmit.
Recommendation:
X2X Link:
Max. 5
POWERLINK:
Max. 7
Data type
Values
USINT
1 to 7
Default: 1
Delay time
Name:
ForwardDelay
Register "ForwardDelay" is used to specify the delay time in µs. This is the amount of time the module has to
wait after sending a sequence until it is permitted to write new data to the MTU in the following bus cycle. The
program routine for receiving sequences from a module can therefore be run in a task class whose cycle time is
slower than the bus cycle.
Data type
Values
UINT
0 to 65535 [µs]
Default: 0
Sequence 1
Sequence 2
Sequence 3
Step I
Step II
Step III
Step IV
Step V
Time
Time
Sequence 1
Sequence 2
Sequence 3
Step I
Step II
Step III
Step IV
Step V
Step I
Step II
Step III
Step IV
Step V
Step I
Step III
Step IV
Step V
Step I
Step II
Step III
Step IV
Step V
Step I
Step II
Step III
Step IV
Step V
Step II
Bus cycle 1
Bus cycle 2
Bus cycle 3
Bus cycle 4
Bus cycle 5
Bus cycle 6
Bus cycle 7
Bus cycle 8
Bus cycle 9
Bus cycle 10
Bus cycle 1
Bus cycle 2
Bus cycle 3
Bus cycle 4
Bus cycle 5
Bus cycle 6
Bus cycle 7
Bus cycle 8
Bus cycle 9
Bus cycle 10
Figure 59: Effect of ForwardDelay when using Flatstream communication with the Forward function
In the program, it is important to make sure that the CPU is processing all of the incoming InputSequences and In-
putMTUs. The ForwardDelay value causes delayed acknowledgment in the output direction and delayed reception
in the input direction. In this way, the CPU has more time to process the incoming InputSequence or InputMTU.
