Object Mapping In The Transfer Buffer (Objects 2110-2113) - Bosch Rexroth ID 40 Manual

Table 28: Buffer status register 210x/02
Bit 7 6
S: Buffer status
0 = Data not yet transmitted
1 = Data exchange in progress
2 = Data exchange complete
3 = Data exchange interrupted due to error More information can be
found in Chapter 9.17.4 "Pre-defined error field (object 1003)"
4–7 = Not used, ignored.
X: Reserved, set to 0
9.5.2 Object mapping in the transfer buffer (objects 2110–2113)
The buffer mappings are available in the 211x objects, whereby x+1 stands for the
number of each transfer buffer.
The buffer mapping determines the data blocks where the payload of the transfer
buffer is entered or read. See Chapter 5 "SLK storage" for the meaning of data
blocks.
Up to 254 data blocks can be assigned to one transfer buffer. A data block is
determined by the following:
Table 29: Buffer mapping 211x/01 to 211x/FE
Bit 31
The data blocks are specified in accordance with Chapter 7.7 "Addressing data in
the ID 40 system". However, since the address/byte count are coded together with a
32-bit value, the SLK data is reduced to 18 bits (bit 14 to bit 31), and the byte count
to 14 (bit 0–13). Despite this restriction to the value ranges, all areas described in
Chapter 5 "SLK storage" can be accessed.
Address and byte count are combined and entered into the 32-bit value of the
mapping object by multiplying the address value by 0x4000 and adding the byte
count to the result.
The address ranges of the SLK can be found in Chapter 9.5.3 "SLK address table".
The number of specified data blocks are found in subindex 00 of the buffer mapping
object. When the number is 0, the transfer buffer is deactivated since there are no
mappings.
The following figure shows the relationships between transfer buffer, buffer mapping
and MDT memory. The data blocks distributed throughout the MDT are seamlessly
strung together in the buffer object. The data blocks can only be reassigned using
the mapping information.
The SLK verifies the total length of the transfer buffer using the sum of the byte
counts in the mapping object. Any deviations trigger a corresponding error message.
5 4 3
X
... 14
Address
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2 1 0
S
13 ... 0
Byte count