User's Manual

Turbo PMAC User Manual
254 Turbo PMAC Computational Features
Intermediate Working Form:
48-Bit Floating Point
(PMAC Handles all type conversions automatically)
1
2
S
G
N
1
4
1
8
... MANTISSA EXPONENT
XY
36 12
48
24
20
16
12
8
4
1
I & M-Variables
P & Q-Variables, Program Constants
36 12
48
24
20
16
12
8
4
1
I & M-Variables
P & Q-Variables
36 12
PMAC Program Mathematical Calculations
For All Motion and PLC Programs
Except Fixed-Point Compiled PLC Lines
In
p
uts to Calculations Out
p
uts from Calculations
However, when Turbo PMAC is doing calculations with L-variables in a compiled PLC program (PLCC)
it uses a 24-bit fixed-point format for the intermediate form of the calculation. This gives Turbo PMAC
the ability to perform the calculations extremely quickly. L-variable calculations are about 10 times faster
than equivalent calculations using intermediate floating-point data formats.
Intermediate Working Form:
Signed 24-Bit Integer
S
G
N
24
20
16
12
8
4
1
L-Variables
PMAC Program Mathematical Calculations
Fixed Point Compiled PLC
Program Lines Only
In
p
uts to Calculations Out
p
uts from Calculation
s
24
20
16
12
8
4
1
L-Variables
S
G
N
S
G
N
24
Program line may only contain L-Variables
and integer constants in range
All values - in,out, and intermediate -
must stay in range - 8,388,608 to 8,388,607
Calculations are about 10 times faster than
equivalent calculations in floation point