X90 mobile modules
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X90 mobile system User's manual V 1.20 - Translation of the original manual
Details/Background
1. Illegal SequenceCounter size (counter offset)
Error situation: MTU not enabled
If the difference between SequenceCounter and SequenceAck during transmission is larger than permitted, a
transfer error occurs. In this case, all unacknowledged sequences must be repeated with the old Sequence-
Counter value.
2. Checking an acknowledgment
After an acknowledgment has been received, a check must verify whether the acknowledged sequence has
been transmitted and had not yet been unacknowledged. If a sequence is acknowledged multiple times, a
severe error occurs. The channel must be closed and resynchronized (same behavior as when not using
Forward).
Information:
In exceptional cases, the module can increment OutputSequenceAck by more than 1 when using
Forward.
An error does not occur in this case. The CPU is permitted to consider all sequences up to the
one being acknowledged as having been transferred successfully.
3. Transmit and receive arrays
The Forward function has no effect on the structure of the transmit and receive arrays. They are created and
must be evaluated in the same way.
