6 User Program
System Manual Modular Systems
Page 42 of 114
HI 800 191 E Rev. 2.02
i
The user is responsible for ensuring that the watchdog time includes a sufficient reserve time.
This should allow the user to manage the following situations:
Variations in the user program's cycle time
Sudden, strong cycle loads, e.g., due to communication.
Expiration of time limits during communication.
During a reload, the global and local variables should be assigned the values of the
corresponding variables from the previous project version. Names of local variables contain the
POU instance names.
This procedure has the following consequences, if names are changed and loaded into the PES
by performing a reload:
Renaming a variable has the same effect as deleting the variable and creating a new one,
i.e., it results in an initialization process. This is also the case for retain variables. The
variables lose their current value.
Renaming a function block instance results in initializing all variables, even retain variables,
and all function block instances.
Renaming a program results in initializing all contained variables and function block
instances.
This behavior may have unintended effects on one or multiple user programs and
therefore on the plant to be controlled!
Conditions for Using the Reload Function
A license is required to use the reload feature.
The following project modifications can be transferred to the controller by performing a reload:
Changes to the user program parameters.
Changes to the logic of the program, function blocks and functions.
Changes that allows a reload in accordance with Table 21.
Changes to
Type of change
Add
Delete
Change of
the initial
value
Assignment of
other variables
Assigning global variables to
User programs
System variables
I/O channels
Communication protocols
-
-
-
-
safe
ethernet
-
-
-
SOE
-
-
Communication protocols
-
-
n.a.
n.a.
User programs
**
n.a.
n.a.
System ID, rack ID
-
IP addresses
-
User accounts and licenses
Reload possible
- Reload impossible
** Reload possible, but the controller must still contain at least one user program
n.a. non-applicable
Table 21: Reloading after Changes
