Siemens SINUMERIK 840Di Function Manual page 1225

• The events entered in the diagnostic buffer are automatically transmitted to
• The PLC user program can also use SFCs (System Function Calls) to enter messages in
• The events are entered in the interrupt buffer.
An FC (FC 10) for message acquisition is prepared in conjunction with the basic program.
This FC records events, subdivides them into signal groups and reports them to the HMI via
the interrupt buffer.
The message acquisition structure is shown in the figure "Acquisition and signaling of PLC
events".
The features include:
• Bit fields for events related to the VDI interface are combined in a single data block (DB2)
• Bit fields are evaluated at several levels by FC10.
• The scope of the user bit fields (user area) is set by default to 10 areas with 8 bytes each,
Acknowledgment concept
The following acknowledgment procedures are implemented for error and operational
messages:
Operating messages are intended for the display of normal operating states as information
for the user. Acknowledgment signals are, therefore, not required for this type of message.
An entry is made in the diagnostic buffer for incoming and outgoing messages. The HMI
maintains an up-to-date log of existing operating messages using the identifiers "operating
message arrived" and "operating message gone".
PLC Basic Program Solution Line (P3 sl)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
human machine interface systems (OP or MMC) via the bus systems once these have
issued a ready signal (message service). Transfer to the node ready is a function of the
PLC operating system. Receipt and interpretation of the messages is executed by the
HMI software.
the diagnostic buffer or ALARM S/ALARM SQ buffer.
The associated message texts must be stored on the OP or HMI.
with bit fields for user messages.
– Evaluation 1; Acquisition of group signals
A group signal is generated for each group of signals if at least one bit signal is set to
"1". This signal is generally linked to the disable signal of the VDI interface (on
modules with diagnostic functions). The group signals are acquired completely in
cycles.
– Evaluation 2; Acquisition of interrupt messages
A fixed specification exists to define which signals in a group generate an interrupt
message when they change from "0" to "1".
– Evaluation 3; Acquisition of operating signals
A fixed specification exists to define which signals in a group generate an operational
message.
but the number of areas can also be adjusted to suit the requirements of the machine
manufacturer via basic program parameters in FB 1.
Detailed Description
2.6 Interface structure
2-31