X20 system modules • Bus controllers • X20BC0043-10
X20 system User's Manual 3.10
517
4.5.3.8 Node number and transfer rate
Node numbers and transfer rates are configured using the two bus controller number switches.
The transfer rate can be specified in two ways:
•
Automatic detection by bus controller (see 4.5.3.9 "Automatic transfer rate detection" on page 517)
•
Fixed definition by user (see 4.5.3.10 "Setting the transfer rate" on page 518)
Switch position
Node number
Transfer rate
0x00
Not allowed
-
0x01 - 0x7F
1 - 127
Automatically set by the bus controller (default) or fixed setting
by the user
0x80 - 0x88
-
Sets a fixed transfer rate
0x89
-
Sets automatic transfer rate detection
0x8A - 0x8F
Not allowed
-
0x90
Clearing the parameters
See section 4.5.3.12 "Deleting parameters" on page 520
-
0x91
Not allowed
-
0x92
Save configuration
1)
See section 4.5.3.11 "Save auto-
matic configuration" on page 519
-
0x93 - 0xFF
Not allowed
-
Table 121: Node numbers and transfer rate
1)
This function is available starting with Hardware version E0 or Firmware version V0001.0107.
4.5.3.9 Automatic transfer rate detection
After booting, the bus controller goes into "Listen only" mode. This means the bus controller behaves passively
on the bus and only listens.
The bus controller attempts to receive valid objects. If receive errors occur, the controller switches to the next
transfer rate in the lookup table.
If no objects are received, all transfer rates are tested cyclically. This procedure is repeated until valid objects are
received.
Lookup table
The controller tests the transfer rate according to this table. Beginning with the starting transfer rate (1000 kbit/s),
the controller switches to the next lower transfer rate. At the end of the table, the bus controller restarts the search
from the beginning.
Transfer rate
1000 kbit/s
800 kbit/s
500 kbit/s
250 kbit/s
125 kbit/s
100 kbit/s
50 kbit/s
20 kbit/s
10 kbit/s
Table 122: Transfer rate lookup table
Summary of Contents for X20 System
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