Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 187)

Chapter 11
Using Data Handling Instructions
11–4
P 0 0 0 F R D S R C
N 1 4 0 0 0 0 H
P 0 0 0 F R D D E S T
N 1 2 0
Important: Always provide filtering of all BCD input devices prior to
performing the FRD instruction. The slightest difference in
point-to-point input filter delay can cause the FRD instruction to
overflow due to the conversion of a non-BCD digit.
Example 1
In the following example, the two rungs cause the controller to verify that the
value I0 remains the same for two consecutive scans before it executes the
FRD. This prevents the FRD from converting a non-BCD value during an
input value change.
Important: To convert numbers larger than 9999 BCD, the source must be
the Math Register (S13). You must reset the Minor Error Bit
(S5/0) to prevent an error.
Ladder Rungs
]/[
S:1
15
EQU
EQUAL
Source A
N7:1
0
Source B I:0.0
0
MOV
MOVE
Source
I:0.0
0
Dest N7:1
0
FRD
FROM BCD
Source
I:0.0
0000
Dest N7:2
0
1
ENT
ANB
0 1
FUN
To enter the function code, press: