309
Conversion Instructions
Section 5-20
DM 6144 to DM 6655 cannot be used for R.
Description
SCL3(––) is used to linearly convert a 4-digit BCD value to 4-digit signed
hexadecimal. SCL3(––) converts the BCD value according to a specified lin-
ear relationship. The conversion line is defined by the y-intercept and the
slope of the line specified in the parameter words P1 to P1+2.
When the execution condition is OFF, SCL3(––) is not executed. When the
execution condition is ON, SCL3(––) converts the 4-digit BCD value in S to
the 4-digit signed hexadecimal value on the line defined by the y-intercept (0,
P1) and the slope (P1+2
÷
P1+1) and places the result in R. The result is
rounded off to the nearest integer.
The content of S can be 0000 to 9999, but S will be treated as a negative
value if CY=1, so the effective range of S is actually –9999 to 9999. Be sure to
set the desired sign in CY using STC(40) or CLC(41).
Parameter words P1+3 and P1+4 define upper and lower limits for the result.
If the result is greater than the upper limit in P1+3, then the upper limit is writ-
ten to R. If the result is less than the lower limit in P1+4, then the lower limit is
written to R.
Note
The upper and lower limits for a 12-bit Analog Input Unit would be 07FF and
F800.
The following table shows the functions and ranges of the parameter words:
Note
Do not set 0000 for
∆
X (4 digits BCD) in the second word (P1+1). The con-
tents of P1+1 is used for division and correct conversion cannot be obtained
when dividing by 0000. Correct results also cannot be obtained if a hexadeci-
mal value is used. Always use BCD data between 0001 and 9999 for P1+1.
The following diagram shows the source word, S, converted to R according to
the line defined by the point (0, P1) and slope
∆
Y/
∆
X.
Parameter
Function
Range
P1
x-intercept (signed hex.)
8000 to 7FFF (–32,768 to 32,767)
P1+1
∆
X (BCD)
0001 to 9999
P1+2
∆
Y (signed hex.)
8000 to 7FFF (–32,768 to 32,767)
P1+3
Upper limit (signed hex.)
8000 to 7FFF (–32,768 to 32,767)
P1+4
Lower limit (signed hex.)
8000 to 7FFF (–32,768 to 32,767)
S
Value after conversion
(Signed hexadecimal)
R
Value before con-
version (BCD)
Y-intercept
∆
X
∆
Y
Lower limit
Upper limit
