Status Var And Force Var With The Op3 - Siemens SIMATIC HMI OP3 Equipment Manual

STATUS VAR and FORCE VAR with the OP3

Access to PLC
With its PU functions STATUS VAR and FORCE VAR, the OP3 provides
operand values
means of displaying and modifying operand values supplied by a connected
PLC by means of standard screens. In online mode, this means that PLC
operands can be edited directly on the OP3 without having to connect a
programming unit or a PC to the PLC.
STATUS VAR can be used only to display SIMATIC S7 operands.
FORCE VAR is used to display the SIMATIC S7 operands and to modify
their variable values and to transfer them back to the PLC.
MPI address
After the functions STATUS VAR or FORCE VAR have been called, OP3
prompts you to type in the MPI address of the PLC. The default value is ad-
dress 2. You can select any SIMATIC S7 on the MPI network, even those that
have not been configured.
In this way, one further, dynamic connection is possible from the OP3 to a
SIMATIC S7 on the MPI network, in addition to a maximum of two perma-
nent, configured connections.
FORCE VAR You call FORCE VAR by means of the standard screen ForceVAR. You call
STATUS VAR STATUS VAR by means of the standard screen StatVAR. Figure 9-1
illustrates, by way of an example, how PLC operands are displayed on the
OP3.
Format field Value field
Figure 9-1
Operator Panel OP3
Edition 11/99
Operand field
Updating in progress
DB34 DBWxx *
INT=999
Example of PLC Operand Display
9
9-1