BECKHOFF CX1100-000x - Manual (Page 33)

Product overview
Embedded PC 31
Free Run:
not implemented. Reserved for future use..
K-Bus error code K-Bus error argument
If the K-Bus operation fails (bad terminal, missing end-terminal, severe EMC interference), an error flag is raised in
the GCB and after a K-Bus reset, these two bytes contain the error code and error argument of the occurred fault - if
it still persists.
K-Bus base ptr Inputs / K-Bus base ptr Outputs
These two byte values contain the starting offset for the K-Bus input and output process image area. In most cases
the default offsets should be left unchanged. When changing one of these offsets, a "Remap" or "Reset node" in the
GCB service is needed. Also care must be taken not to overlap with the IP-Link process image area, because in the
CB IP-Link the offset pointers for these areas may also be changed. The Beckhoff automation software TwinCAT
makes use of this base ptr feature and compacts the I/O images in the best way possible.
K-Bus cycle count
This two-byte counter is incremented with each I/O-cycle.
K-Bus cycle time
This is the time elapsed between the initiation and termination of an I/O process image update (K-Bus + IP-Link ).
The time is recorded in units of microseconds and starts with writing a new cycle request to the field "PD cycle
request" and it stops with the termination response in the field "PD cycle ready", in case of CX1100-0002. In case of
CX1100-0003, this time reflects only the K-Bus portion of the total I/O time.
K-Bus bus status
This byte value can take only two states:
1. Byte = 0 → K-bus is ok
2. Byte ≠ 0 → K-bus fault
This information is also reflected in the "Processdata error" field (bit0) of the GCB.
Retry counter
This is a retry counter which is incremented each time the microcontroller needs to redo a cycle because of a
communication error. This counter can be used for judgment of the K-Bus signal quality.