Iec 61131-3 Second edition 2003-01 Programmable controllers – Part 3: Programming languages

Figure 11 a) - Graphical use of a function block name as an input variable
(table 33, feature 5b)
IEC 2481/02
Copyright International Electrotechnical Commission 
Provided by IHS under license with IEC
Not for Resale
No reproduction or networking permitted without license from IHS
--``````-`-`,,`,,`,`,,`---

---

– 74 –
61131-3 
 IEC:2003(E)
FUNCTION_BLOCK
+--------------+ (* External interface *)
| INSIDE_B |
TON---|I_TMR----I_TMR|---TON
BOOL--|TMR_GO EXPIRED|---BOOL
+--------------+
I_TMR (* Function Block body *)
+-----+
| TON |
TMR_GO--|IN Q|---EXPIRED
|PT ET|
+-----+
END_FUNCTION_BLOCK
FUNCTION_BLOCK
+--------------+ (* External interface *)
| EXAMPLE_B |
BOOL---|GO DONE|---BOOL
+--------------+
E_TMR (* Function Block body *)
+-----+ I_BLK
| TON | +---------------+
|IN Q| | INSIDE_B |
t#100ms---|PT ET| E_TMR---|I_TMR-----I_TMR|
+-----+ GO------|TMR_GO EXPIRED|---DONE
+---------------+
END_FUNCTION_BLOCK
Figure 11 b) - Graphical use of a function block name as an in-out variable
(table 33, feature 6b)
IEC 2482/02
Copyright International Electrotechnical Commission 
Provided by IHS under license with IEC
Not for Resale
No reproduction or networking permitted without license from IHS
--``````-`-`,,`,,`,`,,`---

---

61131-3 
 IEC:2003(E)
– 75 –
FUNCTION_BLOCK
+--------------+ (* External interface *)
| INSIDE_C |
BOOL--|TMR_GO EXPIRED|---BOOL
+--------------+
VAR_EXTERNAL X_TMR : TON ; END_VAR
X_TMR (* Function Block body *)
+-----+
| TON |
TMR_GO---|IN Q|---EXPIRED
|PT ET|
+-----+
END_FUNCTION_BLOCK
PROGRAM
+--------------+ (* External interface *)
| EXAMPLE_C |
BOOL---|GO DONE|---BOOL
+--------------+
VAR_GLOBAL X_TMR : TON ; END_VAR
I_BLK (* Program body *)
+---------------+
| INSIDE_C |
GO------|TMR_GO EXPIRED|---DONE
+---------------+
END_PROGRAM
NOTE The PROGRAM declaration mechanism is defined in 2.5.3.