Statement List (STL) - DCE FEL ČVUT v Praze

10.18 MCRA Activate MCR Area
Format
Description
Status word
Example
Important Notes on Using MCR Functions
MCRA
Program Control Instructions
MCRA (Master Control Relay Activation) energizes the MCR dependency for the
instructions following after it. The instruction MCRA must always be used in
combination with the instruction MCRD (Master Control Relay Deactivation). The
instructions programmed between MCRA and MCRD are dependent upon the signal
state of the MCR bit.
The instruction is executed without regard to, and without affecting, the status word
bits.
BR CC 1 CC 0 OV OS OR STA RLO /FC
writes: - - - - - - - - -
STL Explanation
MCRA //Activate MCR area.
A I 1.0
MCR( //Save RLO in MCR stack, open MCR area. MCR = "on" when RLO=1 (I 1.0 ="1");
MCR = "off" when RLO=0 (I 1.0 ="0")
A I 4.0
= Q 8.0 //If MCR = "off," then Q 8.0 is set to "0" regardless of I 4.0.
L MW20
T QW10 //If MCR = "off," then "0" is transferred to QW10.
)MCR //End MCR area.
MCRD //Deactivate MCR area.
A I 1.1
= Q 8.1 //These instructions are outside of the MCR area and are not dependent upon
the MCR bit.
Statement List (STL) for S7-300 and S7-400 Programming
A5E00706960-01 10-23