707
Data Control Instructions
Section 3-18
Negative Values
An Analog Input Unit actually inputs values from FF38 to 1068 hexadecimal
for 0.8 to 5.2 V. SCL(194), however, can handle only unsigned binary values
between 0000 and FFFF hexadecimal, making it impossible to use SCL(194)
directly to handle signed binary values below 1 V (0000 hexadecimal), i.e.,
FF38 to FFFF hexadecimal. In an actual application, it is thus necessary to
add 00C8 hexadecimal to all values so that FF38 hexadecimal is represented
as 0000 hexadecimal before using SCL(194), as shown in the following exam-
ple.
In this example, values from 0000 to 00C8 hexadecimal will be converted to
negative values. SCL(194), however, can output only unsigned BCD values
from 0000 to 9999, so 0000 BCD will be output whenever the contents of
D00000 is between 0000 and 00C8 hexadecimal.
(BCD)
(BIN)
(BCD)
(BIN)
P1: D00100
P1+1: D00101
P1+2: D00102
P1+3: D00103
Contents of D00200 (R)
Contents of CIO 0200 (S)
Point A
Point B
P1
R
(BCD)
(BIN)
(BCD)
(BIN)
P1: D00100
P1+1: D00101
P1+2: D00102
P1+3: D00103
+
+00C8 He
x
The value in CIO
0200 plus 00C8
hexadecimal
Point A (00C8 Hex
→
0000 (BCD))
Point B (1068 Hex
→
0300 (BCD))
Contents of D 00000 (S)
Point A
Point B
Contents of D 00200 (R)
Summary of Contents for CJ1G-CPUxx
Page 3: ...iv N o t i c e ...
Page 5: ...vi ...
Page 21: ...xxii Conformance to EC Directives 6 ...
Page 35: ......
Page 1131: ...1110 CJ series Instruction Execution Times and Number of Steps Section 4 2 ...