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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.
3333 333
FRD
FROM BCD
Source
Dest
FRD
FROM BCD
Source S:13
00000000
Dest
Output Instruction
SLC 5/02 and higher Processors
and MicroLogix 1000 controllers
Output Instruction
Fixed and SLC 5/01
Processors
Data Handling Instructions
4–7
]/[
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
0
Dest N7:2
0
In the above example, the two rungs cause the processor to verify that the value at
I:0.0 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.
Note To convert numbers larger than 9999 BCD, the source must be the Math Register
(S:13). You must reset the Minor Error bit (S:5.0) to prevent an error.
Changes to the Math Register, S:13 and S:14
Used as the source for converting the entire number range of a register.
Example 1
The BCD value 9760 at source N7:3 is converted and stored in N10:0. The
maximum source value is 9999, BCD.
The source value is displayed
in BCD format.
9 7 6 0
9 7 6 0 N7:3 4–digit BCD 1001 0111 0110 0000
N10:0 Decimal 0010 0110 0010 0000
FRD
FROM BCD
Source N7:3
9760
Dest N10:0
9760
3 3333
PrefaceInstruction Set Reference Manual
4–8
Example 2
The BCD value 32760 in the math register is converted and stored in N7:0. The
maximum source value is 32767, BCD.
0 0 0 3 2 7 6 0
3 2 7 6 0
0 01515 5–digit BCDS:14 S:13
0000 0000 0000 0011 0010 0111 0110 0000
N7:0 Decimal 0111 1111 1111 1000
FRD
FROM BCD
Source S:13
00032760
Dest N7:0
32760
S:13 and S:14 are displayed
in BCD format.
You should convert BCD values to integer before you manipulate them in your
ladder program. If you do not convert the values, the processor manipulates them as
integers and their value is lost.
Note If the math register (S:13 and S:14) is used as the source for the FRD instruction
and the BCD value does not exceed 4 digits, be sure to clear word S:14 before
executing the FRD instruction. If S:14 is not cleared and a value is contained in
this word from another math instruction located elsewhere in the program, an
incorrect decimal value will be placed in the destination word.
3333 333
Data Handling Instructions
4–9
Clearing S:14 before executing the FRD instruction is shown below:
CLR
CLEAR
Dest S:14
0
FRD
FROM BCD
Source S:13
00001234
Dest N7:0
1234
S:13 and S:14 are
displayed in BCD
format.
MOV
MOVE
Source N7:2
4660
Dest S:13
4660
] [
I:1
 0 0001 0010 0011 0100
0000 0100 1101 0010
When the input condition is set (1), a BCD value (transferred from a 4-digit
thumbwheel switch for example) is moved from word N7:2 into the math register.
Status word S:14 is then cleared to make certain that unwanted data is not present
when the FRD instruction is executed.
PrefaceInstruction Set Reference Manual
4–10
Radian to Degrees (DEG)
Use this instruction to convert radians (source) to degrees 
and store the result in the destination. The following formula applies:
Source � 180/Π
where Π = 3.141592
Use this instruction with SLC 5/03 (OS302), SLC 5/04 (OS401), and SLC 5/05
processors.
Entering Parameters
• Source is the integer and/or floating point values.
• Destination is the address of the word where the data is to be stored.
Updates to Arithmetic Status Bits
With this Bit: The Processor:
Carry (C) always resets.
Overflow (V) sets if overflow generated or an unsupported input is detected;
otherwise resets
Zero (Z) sets if the result is zero; otherwise resets
Sign (S) sets if the result is negative; otherwise resets
333
Radians to Degrees
Source
Dest
DEG
Output Instruction
Data Handling Instructions
4–11
Degrees to Radians (RAD)
Use this instruction to convert degrees (source) to radians and store the result in the
destination. The following formula applies:
Source � Π/180
where Π = 3.141592
Use this instruction with SLC 5/03 (OS302), SLC 5/04 (OS401), and SLC 5/05
processors processors.
Entering Parameters
• Source is the integer and/or floating point values.
• Destination is the address of the word where the data is to be stored.
Updates to Arithmetic Status Bits
With this Bit: The Processor:
Carry (C) always resets.
Overflow (V) sets if overflow generated or an unsupported input is detected;
otherwise resets
Zero (Z) sets if the result is zero; otherwise resets
Sign (S) sets if the result is negative; otherwise resets
333
Degress to Radians
Source
Dest
RAD
Output Instruction
PrefaceInstruction Set Reference Manual
4–12
Decode 4 to 1 of 16 (DCD)
When executed, this instruction sets one bit of the destination word. The particular
bit that is turned on depends on the value of the first four bits of the source word.
See the table below.
Use this instruction to multiplex data in applications such as rotary switches,
keypads, and bank switching.
 Source Destination
Bit 15–04 03 02 01 00 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
 x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1
 x 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0
 x 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0
 x 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0
 x 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0
 x 0 1 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0
 x 0 1 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0
 x 0 1 1 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0
 x 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0
 x 1 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0
 x 1 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0
 x 1 0 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0
 x 1 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0
 x 1 1 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0
 x 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 x 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Entering Parameters
• Source is the address that contains the bit decode information. Only the first
four bits (0–3) are used by the DCD instruction. The remaining bits may be
used for other application specific needs. Change the value of the first four bits
of this word to select one bit of the destination word.
• Destination is the address of the word where the data is to be stored.
Updates to Arithmetic Status Bits
Unaffected.
3333 333
DCD
DECODE 4 to 1 of 16
Source
Dest
Output Instruction
Data Handling Instructions
4–13
Encode 1 of 16 to 4 (ENC)
When the rung is true, this output instruction searches the source from the lowest to
the highest bit, and looks for the first set bit. The corresponding bit position is
written to the destination as an integer as shown in the table below.
 Source Destination
Bit 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 15–04 03 02 01 00
 x x x x x x x x x x x x x x x 1 x 0