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4.14.3
Each PDO telegram contains 8 Bytes of usable data. According to the worst case, this
results in a maximum telegram length of 140 bits. The maximum telegram run time of
the PDO's is thus stipulated via the set baud rate.
As a function of the set baud rate and the transmission interval of the TxPDO's se-
lected, the following bus loads results:
Baud rate /
Attention! A bus load >100% means that a telegram cannot be dispatched com-
This calculation must be done for each TxPDO. The sum of all the TxPDO's decides on
the entire bus load. The bus load must be designed in such a way that any telegram
repetitions for transmission errors are possible without exceeding the bus capacity.
Note:
06/05
06/05
Capacity planning of the system bus
Baud rate /
kBaud
1000
500
250
125
100
50
Bus load as a function of the transmission for one TxPDO in %
kBaud
1ms
2ms
1.000
14
7
500
28
14
250
56
28
125
112
56
100
140
70
50
280
140
pletely between two transmission times.
To facilitate capacity planning, an Microsoft Excel file with the name
"Load_Systembus.xls" is available.
Capacity planning
Telegram run time / μs
140
280
560
1120
1400
2800
Capacity of the system bus
3ms
4ms
5ms
4.7
3.5
2.8
9.3
7
5.6
18.7
14
11.2
37.3
28
22.4
46.7
35
28
93.3
70
56
Such a setting is not permitted!
6ms
7ms
8ms
9ms 10ms
2.3
2
1.8
1.6
4.7
4
3.5
3.1
9.3
8
7
6.2
18.7
16
14
12.4
23.3
20
17.5
15.6
46.7
40
35
31.1
1.4
2.8
5.6
11.2
14
28
47
47
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