Internal Reference Id For Controller And Hmi Tags - Siemens S7-1200 Programming Manualline

2 S7-1200/1500 Innovations

2.12 Internal reference ID for controller and HMI tags

1. System constants of a controller can be found in the "PLC tags –
Default tag table" folder.
2. The system constants are in a separate tab in the "Default tag table".
3. In this example the symbolic name "Robot_arm_left" was assigned for a DI
module.
You can also find the module under this name in the system constant tab.
In the user program "Robot_arm_left" is interconnected with the "GET_DIAG"
diagnostic block.
Note You will find further information in the following entry:
What meaning do the system constants have for the S7-1200/1500 in STEP 7
(TIA Portal)?
http://support.automation.siemens.com/WW/view/en/78782836
2.12 Internal reference ID for controller and HMI tags
STEP 7, WinCC, Startdrive, Safety and others integrate into the joint data base of
the TIA Portal engineering framework. Changes of data are automatically accepted
in all the locations in the user program, independent from whether this happens in
a controller, a panel or a drive. Therefore no data inconsistencies can occur.
If you create a tag, the TIA Portal automatically creates a unique reference ID. The
reference ID cannot be viewed or programmed by you. This procedure is internal
referencing. When changing tags (address), the reference ID remains unchanged.
In the figure below the internal reference to the data is displayed schematically.
Figure 2-16: Internal reference ID for PLC and HMI
PLC_1
PLC Symbol
name
Motor_1
Valve_2
NOTE The ID will be invalid if ...
Programming Guideline for S7-1200/1500
V1.2, Entry ID: 81318674
Absolute Internal PLC
address reference ID
I0.0 000123
Q0.3 000138
name is changed.
type is changed.
tag is deleted.
Internal HMI HMI Symbol
reference ID name
009876 Motor_1
000578 Valve_2
HMI_1
Access Connection
mode with PLC
<symbolic PLC_1
access>
<symbolic PLC_1
access>
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