Beckhoff BC8050, Documentation

Page: 62 / 93

Programming
BC8050 und BC8150 62 Version: 3.0.0
Fig. 58: Selecting the data transfer route - AMS
PLC Control can be accessed via Online/Communication Parameters... .
Fig. 59: Selecting the device
5.14 Process image
5.14.1 Modbus Process Image
Default config (without TwinCAT System Manager):
The data of the Modbus slave interface are stored in the allocated section of the BC8x50.
The input data from the master perspective are stored in the controller output section from address
%QB1000 (Modbus address 30001, depending on master).
The output data from the master perspective are stored in the controller input section from address %IB1000
(Modbus address 42049 - depending on master).
The maximum data length is 512 bytes input and 512 bytes output.
Recommendation
We recommend limiting Modbus access to the flag area of the controller, master address 3 16385
dec
or 4
16385
dec
(3 4001
hex
or 4 4001
hex
, see Modbus interface [
}
65] ). The flag area has a size of 4 kB and is not
watchdog-triggered. The flag area is available for reading or writing.
5.14.2 KS8000 Process Image
Default config (without TwinCAT System Manager):
The data of the KS8000 slave interface are stored in the allocated section of the BC8x50.
The input data from the master perspective are stored in the controller output section from address
%QB1000 (address offset 0 from the master perspective).