Page Mode
CAN-CBM-DP
Software Manual Rev. 2.0
43
6. Page Mode
Note:
Page Mode can only be used, if the configuration tool Siemens SIMATIC Manager for S7
is used!
6.1 Properties
The Page Mode offers the chance to address more CAN identifiers than can be stored in a PROFIBUS
telegram (that means more than 48). The number of possible identifiers is only limited by the free
memory available on the PLC and the CAN gateway.
By means of the Communication Window, too, more than 48 identifiers can be transmitted. You can
only transmit one CAN frame each per PLC cycle, however, via the Communication Window, therefore
it is generally more suitable for infrequent accesses, such as one-time configurations.
Because of the additional protocol expenditure the handling of the Page Mode is slightly more
complicated than the standard operation of the gateway. The data exchange between PROFIBUS and
CAN requires two cycles instead of one PLC cycle, because of the required handshake.
In order to simplify the handling of the Page Mode, function blocks and data blocks which control the
Page Mode are contained in the package.
6.2 Activation
Before you activate the Page Mode you have to integrate the according functional and data blocks into
your PLC program. Please read the following chapters carefully to get an insight into the mode of
operation and be able to use the contained functional and data blocks according to your demands.
The Page Mode is activated, for instance, via the SIMATIC manager (SIEMENS PLC, S7) during the
configuration of the gateway in the DP-slave properties window (refer to page 24).
6.3 Communication Window in Page Mode
When specifying
Communication Window
the Communication Window can be activated in the DP-
salve properties window while configuring the gateway.
The Communication Window is set up and handled like in normal operation (see page 31). The
Communication Window must be defined in the last segment, however.
Note:
Using the Communication Windows (
CW
) is only useful to configure the connected
CAN-devices. If the connected CAN-devices have been configured, the normal page
mode (
PM
) is to be preferred
Note:
The CAN-CBM-DP-module with the order no. C.2844.05 can handle 29-Bit-CAN-
identifiers. A 29-bit identifier requires
four
bytes and bit 29 must be set to ‘1’ (counted 0...31
bits), in order to enable the module to distinguish between 11-bit and 29-bit identifiers.