Automationdirect.com DirectLOGIC DL205 Series User Manual

DL205 User Manual, 4th Edition, Rev. B
5–93
Chapter 5: Standard RLL Instructions - Math
1
2
3
4
5
6
7
8
9
10
11
12
13
14
A
B
C
D
Subtract Real (SUBR)
The Subtract Real is a 32-bit instruction that subtracts a real
number, which is either two consecutive V-memory locations or
a 32-bit constant, from a real number in the accumulator. The
result is a 32-bit real number that resides in the accumulator.
Both numbers must be Real data type (IEEE floating point
format).
NOTE: Status flags are valid only until another instruction uses the same flag.
NOTE: The current HPP does not support real number entry with automatic conversion to the 32-bit IEEE
format. You must use DirectSOFT for this feature.
SUBR
A aaa
ý
ý
þ
þ
230
240
250-1
260
ndard RLL
structions
LDR
R22.0
X1
SUBR
R15.0
00000000000000000100000011100000
8421842184218421
8421842184218421
Acc.
40 E0 0000
V1400V1401
Real Val ue
OUTD
V1400
Implies 2 (exp 2)
129 -- 127 = 2
(Hex num b er)
Mantissa (23 bits)Sign Bit
41B0 0000
000041B0
(SUBR)
(Accumulator )
4170 0000
_
000040E0
Acc.
22
(decimal)
_
15
7
1.11 x 2 (exp 2) = 111. binary= 7 decimal128 + 1 = 129
Exponent (8 bits)
DirectSOFT
Load the real number
22.0 into the accumulator.
Subtract the real number
15.0 from the accumulator
contents, which is in real
number format.
Copy the result in the
accumulator to V1400
and V1401.
Discrete Bit Flags Description
SP63 On when the result of the instruction causes the value in the accumulator to be zero.
SP70 On anytime the value in the accumulator is negative.
SP71 On anytime the V-memory specified by a pointer (P) is not valid.
SP72 On anytime the value in the accumulator is an invalid floating point number.
SP73 On when a signed addition or subtraction results in an incorrect sign bit.
SP74 On anytime a floating point math operation results in an underflow error.
SP75 On when a real number instruction is executed and a non-real number was encountered.
Operand Data Type DL250-1 Range DL260 Range
A aaa aaa
V-memory V All. (See page 3-55) All. (See page 3-56)
Pointer P All V-memory (See page 3-55) All V-memory (See page 3-56)
Constant R
-3.402823E+038 to
+ 3.402823E+038
-3.402823E+038 to
+ 3.402823E+038
DS Used
HPP N/A

Automationdirect.com DirectLOGIC DL205 Series Specifications

General

Brand	Automationdirect.com
Model	DirectLOGIC DL205 Series
Category	Controller
Language	English