Siemens SIMATIC S7-200 System Manual page 111

Example: Compare Instructions
S7-200 Instruction Set
Network 1 //Turn analog adjustment potentiometer 0
//to vary the SMB28 byte value.
//Q0.0 is active when the SMB28 value
//is less than or equal to 50.
//Q0.1 is active when the SMB28 value
//is greater than or equal to 150.
//The status indicator is on when
//the comparison is true.
LD I0.0
LPS
AB<= SMB28, 50
= Q0.0
LPP
AB>= SMB28, 150
= Q0.1
Network 2 //Load V memory addresses with
//low values that make the comparisons
//false and that turn
//the status indicators off.
LD I0.1
MOVW - -30000, VW0
MOVD - -200000000, VD2
MOVR 1.012E- -006, VD6
Network 3 //Load V memory addresses with
//high values that make the
//comparisons true and that turn
//the status indicators on.
LD I0.2
MOVW +30000, VW0
MOVD - -100000000, VD2
MOVR 3.141593, VD6
Network 4 //The Integer Word comparison tests
//to find if VW0 > +10000 is true.
//Uses program constants to show the
// different data types. You can also
//compare two values
//stored in programmable memory
//like: VW0 > VW100
LD I0.3
LPS
AW> VW0, +10000
= Q0.2
LRD
AD< - -150000000, VD2
= Q0.3
LPP
AR> VD6, 5.001E- -006
= Q0.4
Chapter 6
97