Page Mode
CAN-CBM-DP
Software Manual Rev. 2.0
52
6.4.7 Data Exchange via Pages 251...n
The user data is read and written via page 251 (decimal) and following. The maximum number of data
pages is 65285.
The structure of the page for output data can differ from the page structure for input data, because the
number of Rx-data can differ from the number of Tx-data.
Byte
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
...
Length
[bytes]
2
6
1
1...8 (here: 4)
1
1...8 (here: 6)
...
Contents
page no.
protocol data
force
Tx_user_data
force
Tx_user_data
...
data of Tx-identifier 1
data of Tx-identifier 2
Example
t
251
...
2
12 34 56 78 (hex)
1
BA 98 76 54 32 10 (hex)
...
Table 6.4.6:
Example of a data page for output data
Bytes 0 to 7 contain the protocol information already mentioned above (refer also to page 48).
Starting with byte 8 in the first segment, the data of the first identifier are transmitted to the gateway.
The data of the next identifier follow directly, that means that only as many data bytes are transmitted
each per identifier as have been defined in
length
!
In the second segment the transmission of data already starts with byte 2, because bytes 2 to 7 do not
contain protocol information.
force
In this byte you can specify the time when the Tx-data is to be transmitted:
force
Transmission
0
1
2
3
4
data is not put out as CAN frame
data is always (following each PROFIBUS telegram) put out as CAN frame
data is only put out as CAN frame, if data was changed
data is put out as CAN frame once *)
data is put out as CAN frame once *)
*) Change between 3 and 4 causes a direct output of data
Table 6.4.7:
Specifying the cause for transmitting Tx-data
Tx_user_data
Here the user data of this Tx-identifier to be transmitted are specified.
