semaphore TBOX LT2-530 Series, User Manual, Page: 81 / 197

Version : 1.09 81
9.3. ModBus address
The ModBus address is the link to the outside world. When equipment must sample Tags in
TB
OX
LT2
,
it uses its ModBus addresses; like TView, SCADA or TWinSoft.
Each Tag has a unique ModBus address. By default TWinSoft proposes a ModBus address.
You can change it if you want.
While being On-line, the value of the Tag can be displayed only when TWinSoft has sent
the program to
TB
OX
LT2
.
The Tag is then available for the outside world at the ModBus address you have declared
9.3.1. ModBus address of System Variables
With System Variables it is a little bit different; they have two ModBus addresses:

One internal and fixed ModBus address. It explains why when you are connected to
TB
OX
LT2
, even without sending a program, you still can see values from the Resources.
The address of these variables is 65280 + ID of the variable.
Example: [AlaRec] = 65280+10=65290

One user definable ModBus address that you modify as you want. When you create a Tag of
system variable, you can change its default ModBus address.
In case you wish to access the Tag, you declare this user ModBus address.
Other Tabs of the Tag configuration refer to menu where the Tag can be declared:
For Alarms, see chapter 12
For Datalogging, see chapter 14
For ModBus Transactions, see chapter 15
About Presentation-write, see next chapter