Description Of Operational Sequences (Details) - Siemens SINUMERIK 840D sl Function Manual

B3: Several operator panels connected to several NCUs, distributed systems - only 840D sl
Operating focus switchover in server mode
A server maintains a permanent link to the NCUs to which it is assigned. The operator can
switch the operating focus from one NCU to another without interrupting the existing link.
Active/passive operating mode
An online operator panel can operate in two different modes:
Active mode: Operator can control and monitor
Passive mode: Operators sees header information and the "passive" identifier.
MCP switchover
As an option, an MCP assigned to the operator panel can be switched over at the same
time.
2.15.2.2

Description of operational sequences (details)

Introduction
The operational sequences are described using identifiers for defined, logical functions
(example: OFFL_REQ_OP/ OK) whose programming application has been described earlier
in this section. The functions are coded in accordance with Section "Defined logical
functions/defines". The functions store values in the interface which can be addressed from
the PLC and the HMI. An operator panel utilizes the online-request interface while competing
for the use of an online interface. Operator panels which are already linked to an NCU utilize
one of the two available online interfaces. Details of these interfaces can be found in Section
"Signal descriptions" and in
References: Lists
In order to illustrate complete operating sequences, the description covers HMI activities
which cannot be influenced as well as modifiable PLC activities.
Operator panel sends request
If the operator panel is already linked online to an NCU (online NCU) and would like to
communicate with another NCU (target NCU), it must first notify the PLC of the online NCU
that it wishes to switch over to the target NCU.
It sends the offline request OFFL_REQ_OP/ OK to the online PLC.
OFFL_CONF_OP/OK:
Online PLC has received the offline request. HMI can now send a request to the target PLC.
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
2.15 Examples
203