Siemens Simatic S7-200 System Manual page 148

S7-200 Programmable Controller System Manual
Example: Single-Segment Pulse Train Operation (PTO)
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Network 1 //On the first scan,
//set the image register bit low and call subroutine 0.
LD SM0.1
R Q0.0, 1
CALL SBR_0
Network 1 //Start of subroutine 0: Configure PTO
//1. Set up the control byte:
// – Select PTO operation.
// – Select single segment operation.
// – Select ms increments.
// – Enable the loading of the pulse count
// and cycle time value.
// – Enable the PTO function.
//2. Set cycle time to 500ms.
//3. Set pulse count to 4 pulses.
//4. Define interrupt routine 0 to be the interrupt
// for processing PTO complete interrupts.
//5. Global interrupt enable.
//6. Invoke PTO operation, PLS0 => Q0.0.
//7. Preload the control byte for subsequent cycle time
//changes.
LD SM0.0
MOVB 16#8D, SMB67
MOVW +500, SMW68
MOVD +4, SMD72
ATCH INT_0, 19
ENI
PLS 0
MOVB 16#89, SMB67