3 ctud, Ctud, Drive plc developer studio – Lenze DDS v2.3 User Manual
Page 307
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Drive PLC Developer Studio
IEC 61131-3 Standard functions
14-15
l
DDS EN 2.3
14.6.3
CTUD
Up and down counter
CU
, CD, RESET, LOAD, QU and QD are of type BOOL, PV and CV are of type INT.
•
If RESET is valid, the counter variable CV will be initialized with 0.
•
If LOAD is valid, CV will be initialized with PV .
•
If positive edge CU is valid, CV will be increased by 1 as long as CV does not cause an
overflow.
•
If positive edge CD is valid, CV will be decreased by 1 as long as CV does not cause an
underflow.
•
QU
returns TRUE if CV has become greater than or equal to PV.
•
QD
returns TRUEif CV has become less than or equal to 0.
CTUD(CU, CD, RESET, LOAD, PV, QU, QD, CV)
Examples
Declaration:
CTUDInst : CTUD;
IL
FBD
CAL CTUDInst(CU:=VarBOOL2, RESET:=VarBOOL32,
LOAD:=VarBOOL4; PV:=VarINT1)
LD CTUDInst.QU
ST VarBOOL5
LD CTUDInst.QD
ST VarBOOL6
LD CTUDInst.CV
ST VarINT2
ST
CTUDInst(CU:=VarBOOL2, RESET:=VarBOOL32, LOAD:=VarBOOL4; PV:=VarINT1);
VarBOOL5:=CTUDInst.QU;
VarBOOL6:=CTUDInst.QD;
VarINT2:=CTUDInst.CV;
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