Micromod Micro-DCI: 53SL5100A Single Loop Controller - Manual (Page 139)

Single Loop Process Controller Instruction Manual
Communications 131
H F00H 5 Represents high precision
floating point values that have a
resolution of one part in 2 billion (31
bits) and a dynamic range of ± 10
38
.
The first four bytes represent a 2’s
complement notation in fractional
form (2
-n
) whose absolute value is
between 0.5 and 0.9999. The fifth
byte is the power of 2 in 2’s
complement notation. Floating point
example: 9CH 00H 00H 00H 07H =
-100. The 2’s complement notation
bit in the 9 = 1 (1001) indicating a
negative number; therefore, 9C
must be re-complemented . 9C =
1001 1100, change 1’s to 0’s and
0’s to 1’s = 0110 0011and add
1=0110 0100 (64H). Fractional
binary weights left to right for 0110
0100 are 0 = 2’s complement
positive, 1 = 2
-1
= 1/2 = 0.5, 1 = 2
-2
= 1/4 = 0.25, 0=0, 0=0, 1 = 2
-5
= 1/32
= 0.03125, 0=0, 0=0. 64H = 0.5 +
0.25 + 0.03125 = 0.78125.
07H=128D, 128D X 0.78125D =
100. A negative sign is assigned (-
100) because the original 2’s
complement binary bit in the 9
(1001) of 9C was set indicating a
negative number.
Address = H Base + (5 X H Number)
= F00H + (5 X H Number)
Address example: H001 location
F00H + (5 X 1) = F00H + 5D = F00H
+ 5H = F05H.
A (F)* 1400H 10 (A)
5 (F)*
The A data format represents text
strings that are 10 characters long.
The F data format represents text
strings that are 5 characters long. Address = A Base + (10 X Number)
= 1400H + (10 X Number)
(for both A and F data types)
Address example: A015 location
1400H + (10 X 15) =
1400H + 150D = 1400H + 96H
1496H.
* F data types are 5 bytes long and are mapped onto A data types.
Table B-3. Instrument Memory Address Scheme
Data
Type
Base
Memory
Address
Byte
Size
Data Format Address Calculation Algorithm