PEB 2091
PEF 2091
Functional Description
Superframe
5
Receive
U Frame
1 isw
2
3
4
6
7
8
1
Superframe
Marker
IOM R Frame
12
24
36
32
48
60
72
84
80
96
No
No
1
49
Possible Start of
Monitor Procedure
Start of
New
Transfer
Start of
New
Transfer
Reset
Reset
ITD04232
Figure 30
Monitor Access with MTO Enabled
Monitor Channel Transmitter and MTO Enabled
The transmitter is reset in 6 ms intervals in the frames shown above. In case the
transmission of a monitor message has not been completed before the transmitter is
reset, the complete message will be lost. A message that has been lost due to the
interruption of a monitor reset will not be retransmitted.
To prevent this loss of monitor messages, the IEC-Q will only commence a monitor
transmission if more than 16 IOM®-2 frames will be available for transmission before the
next reset occurs. Transmission thus does not start during frame numbers 33 … 48 and
81 … 96. To ensure correct transmission the receiver must not delay the receive
procedure for more than the following value:
• 2-byte transmission: max. speed = 8 frames => max. controller (receive) delay =
8 frames.
Monitor Channel Receiver and MTO Enabled
The receiver is reset in 6 ms intervals in the frames shown above. In case the reception
of a monitor message has not been completed before the receiver is reset, the complete
message can be lost because the generation of an abort request can not be guaranteed.
To prevent this loss of monitor messages the PEB 2091 will only commence a monitor
reception (i.e. acknowledge the 1st received byte) if more than 16 IOM®-2 frames will be
available for reception before the next reset occurs. Reception thus does not start during
frame numbers 33 … 48 and 81 … 96. To ensure correct reception, the transmitter must
not delay the receive procedure for more than the following value:
• 2-byte reception: max. speed = 7 frames => max. controller (transmit) delay = 9
frames.
Semiconductor Group
81
Data Sheet 01.99
INFINEON [ Infineon ]
