Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 668

Floating-point Math Instructions
Description
Flags
Precautions
628
ATAN(465) computes the angle (in radians) for a tangent value expressed as
a 32-bit floating-point number in S+1 and S and places the result in R+1 and
R.
(The floating point source data must be in IEEE754 format.)
–1
TAN
S+1
R+1
The result is output to words R+1 and R as an angle (in radians) within the
range of – /2 to /2.
The following diagram shows the relationship between the input data and
result.
Name Label
Error Flag ER
Equals Flag =
Overflow Flag OF
Underflow Flag UF
Negative Flag N
The source data in S+1 and S must be in IEEE754 floating-point data format.
Source (32-bit floating-point data)
S
Result (32-bit floating-point data)
R
R
S: Input data (tangent)
R: Result (radians)
Operation
ON if the source data is not recognized as floating-point
data.
ON if the source data is not a number (NaN).
OFF in all other cases.
ON if both the exponent and mantissa of the result are 0.
OFF in all other cases.
OFF
OFF
ON if the result is negative.
OFF in all other cases.
Section 3-15