Simatic Real Math Instructions; Add Real, Subtract Real - Siemens SIMATIC S7-200 System Manual

SIMATIC Instructions
9.7

SIMATIC Real Math Instructions

Add Real, Subtract Real

L
A
D EN
F
IN1
B
D
IN2
EN
IN1
IN2
S
+R
T
L
-R
221 222 224
Inputs/Outputs
IN1, IN2 VD, ID, QD, MD, SD, SMD, AC, LD, Constant, *VD, *AC, *LD
OUT VD, ID, QD, MD, SD, SMD, AC, LD, *VD, *AC, *LD
Note
Real or floating-point numbers are represented in the format described in the
ANSI/IEEE 754-1985 standard (single-precision). Refer to the standard for more
information.
9-82
The Add Real and Subtract Real instructions add or
subtract two 32-bit real numbers and produce a 32-bit
ADD_R
real number result (OUT).
ENO
In LAD and FBD:
OUT OUT
In STL:
SUB_R
ENO
Error conditions that set ENO = 0: SM1.1 (overflow),
OUT OUT
SM4.3 (run-time), 0006 (indirect address)
These instructions affect the following Special Memory
bits: SM1.0 (zero); SM1.1 (overflow); SM1.2 (negative)
SM1.1 is used to indicate overflow errors and illegal
IN1, OUT
values. If SM1.1 is set, then the status of SM1.0 and
IN1, OUT
SM1.2 is not valid and the original input operands are not
altered. If SM1.1 is not set, then the math operation has
completed with a valid result and SM1.0 and SM1.2
226
contain valid status.
Operands
IN1 + IN2 = OUT
IN1 - IN2 = OUT
IN1 + OUT = OUT
OUT - IN1 = OUT
S7-200 Programmable Controller System Manual
Data Types
REAL
REAL
A5E00066097-02