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Instance DB
S7-GRAPH for S7-300/400 Programming Sequential Control Systems
C79000-G7076-C526-01
15-9
15.10
The Transition Structure
A structure with the following parameters is created in the instance DB for every
transition located in the sequencer of the S7-Graph FB:
Component
Description
Data
Type
Read
int.
Write int.
Read
Ext.
Write Ext.
TV
Transition is valid
BOOL
yes
no
yes
no
TT
Transition is satisfied
BOOL
yes
no
yes
no
TS
Transition switches
BOOL
yes
no
yes
no
CF_IV
The CRIT_FLT entry is invalid
BOOL
yes
no
yes
no
TNO
Indicates the user-defined transition
number
INT
no
no
yes
no
CRIT
Status of the maximum 32 LAD/FBD
elements of the transition in the
current processing cycle
DWORD
yes
no
yes
no
CRIT_OLD
Status of the maximum 32 LAD/FBD
elements of the transition in the
previous processing cycle
DWORD
yes
no
yes
no
CRIT_FLT
Copy of CRIT if an error occurs
DWORD
yes
no
yes
no
"Structure arrays" Option
If you have selected the "Structure arrays" option, an array containing the
structures of the transitions is created.
Array Name
Length in Bytes
G7T
(number of transitions) * 16
Internal access uses the transition number followed by the name of the structure
element.
This means that the following access is possible in conditions or actions:
•
T003.TT
•
T017.CRIT