Siemens SIMATIC S7-200 System Manual page 146

S7-200 Programmable Controller System Manual
Example: High-Speed Counter Instruction
M
A
I
N
S
B
R
0
I
N
T
0
132
Network 1 //On the first scan, call SBR_0.
LD SM0.1
CALL SBR_0
Network 1 //On the first scan, configure HSC1:
//1. Enable the counter.
// - - Write a new current value.
// - - Write a new preset value.
// - - Set the initial direction to count up.
// - - Select the start and reset inputs
// to be active high.
// - - Select 4x mode.
//2. Configure HSC1 for quadrature mode
// with reset and start inputs.
//3. Clear the current value of HSC1.
//4. Set the HSC1 preset value to 50.
//5. When HSC1 current value = preset value,
// attach event 13 to interrupt routine INT_0.
//6. Global interrupt enable.
//7. Program HSC1.
LD SM0.1
MOVB 16#F8, SMB47
HDEF 1, 11
MOVD +0, SMD48
MOVD +50, SMD52
ATCH INT_0, 13
ENI
HSC 1
Network 1 //Program HSC1:
//1. Clear the current value of HSC1.
//2. Select to write only a new current
// and leave HSC1 enabled.
LD SM0.0
MOVD +0, SMD48
MOVB 16#C0, SMB47
HSC 1