Internal Variables - JUMO LOGOSCREEN 601 Manual

4 System variables
4.3

Internal variables

The internal variables can be used in the ST code to implement certain functions.
ext_error
Designation
ext_error
reset_flag
Designation
reset_flag
sys_error
Designation
sys_error
week_day
Designation
week_day
22
Description
Integer variable
The variable indicates errors that occurred during accesses outside the ST module.
In the event of an error, the variable returns a value > 0 (no error = 0).
Description
Boolean variable
The variable is set to TRUE after power-on and is used to initialize variables. Ex-
ample: chapter 7.1 "Selection instructions", page 31
If the ST code is completely run through once without an error after power on, the
variable is set to FALSE. Otherwise, it stays as TRUE.
Debug mode: The first time the program is started in debug mode or after a program
stop, the variable is TRUE. After a second run through, it is set to FALSE.
Description
Real variable
The variable returns an error value if an error occurs during program execution (no
error = 0):
1.00E+37 = general error value
1.0E+37 = underrange (underflow)
2.0E+37 = overrange (overflow)
3.0E+37 = invalid input value
4.0E+37 = division by zero
5.0E+37 = incorrect math value
7.0E+37 = invalid value (general)
Description
Integer variable
The variable includes the current day:
0 = Sunday, 1 = Monday, 2 = Tuesday, 3 = Wednesday, 4 = Thursday, 5 = Friday,
6 = Saturday
The day is derived from the input variable rtc.cdt.