Beckhoff BK3120 User Manual

Extended functions
BK3xx0 77Version: 4.3.0
Exceeding the configuration data length (CfgData)
By default, a maximum of 64 bytes of configuration data is set on the Bus Coupler. Normally, this is only a
problem in very rare cases. In multi-configuration mode, however, this limit is reached with no more than a
30 digital terminals, because each KLxxxx MultiCfgMode module occupies two bytes in the configuration
data, on top of which there is at least one sum byte for digital inputs or for digital outputs.
The maximum lengths of the DP buffers can be changed, although the amount by which a length is
increased has to be subtracted from another, and the sizes must only be modified in 8-byte steps:
Maximum DP buffer sizes
DP buffer Maximum sizes under default settings
Inputs 128 bytes
Outputs 128 bytes
Diagnostic data 64 bytes
Configuration data 64 bytes
Setting via the 2-BYTE PLC interface or KS2000
The maximum DP buffer sizes can be modified in Table 100, although it is necessary for the Bus Coupler to
be reset (power off/power on, or a software reset) before the new value is adopted:
Register Description
2 maximum length of input data
3 maximum length of output data
4 maximum length of diagnosis data
5 maximum length of configuration data
Setting via UserPrmData
The Bus Coupler's reset is carried out automatically if the DP buffers are set using UserPrmData [}35]:
Byte Bit Description
12 4-7 15 dec or 0xF hex: the maximum DP buffer lengths are changed using the values
from UserPrmData 37-40
37 0-7 maximum length of input data
38 0-7 maximum length of output data
39 0-7 maximum length of diagnosis data
40 0-7 maximum length of configuration data
Example1:Notenoughconfigurationdata
128bytesinput
128bytesoutput
80bytesCfgData
48bytesdiagnosisdata
Example2:Notenoughinputdata
160bytesinput
96bytesoutput
64bytesCfgData
64bytesdiagnosisdata
7.6 Bus Coupler versions in multi-configuration mode
Structure of a production machine
Production machines often consist of a machine part that is always present in the machine and of machine
extensions that may be added as options. This division also usually applies as well both to the software (the
control program) and to the hardware (the necessary process signals via Beckhoff Bus Terminals)

Beckhoff BK3120 Specifications

General

Brand	Beckhoff
Model	BK3120
Category	Adapter
Language	English