Convert to BCD (TO_BCD)

This table lists the controllers and applications that support this instruction.

Architecture	Standard applications	Safety applications
CompactLogix 5370, ControlLogix 5570, Compact GuardLogix 5370, and GuardLogix 5570 controllers	Yes	No
CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers	Yes	Yes

The TO_BCD instruction converts a decimal value (0 Less than or equal to

Source

99,999,999) to a BCD value and stores the result in the Destination.

TIP: In Logix Designer version 36, the mnemonic for this instruction changed from TOD to TO_BCD.

Available Languages

Ladder Diagram

Function Block Diagram

Function Block Diagram supports these elements:

FBD Block

Structured Text

This instruction is not available in structured text.

Operands

IMPORTANT: Unexpected operation may occur if:

Output tag operands are overwritten.

Members of a structure operand are overwritten.

Except when specified, structure operands are shared by multiple instructions.

There are data conversion rules for mixing numeric data types within an instruction. See Data conversions.

Ladder Diagram

Operand	Data Type CompactLogix 5370, ControlLogix 5570, Compact GuardLogix 5370, and GuardLogix 5570 controllers	Data Type CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers	Format	Description
Source	SINT INT DINT	SINT INT DINT LINT USINT UINT UDINT ULINT	Immediate tag	Value to convert to BCD 0 Source 99,999,999
Destination	SINT INT DINT	SINT INT DINT LINT USINT UINT UDINT ULINT	tag	Tag to store the result

Function Block Diagram

FBD Block

Operand	Type	Format	Description
TO_BCD tag	FBD_CONVERT	Structure	TO_BCD structure

FBD_CONVERT Structure

Input Member	Data Type	Description
EnableIn	BOOL	Enable input. If cleared, the instruction does not execute and outputs are not updated. Default is set.
Source	DINT	Input to the conversion instruction. Valid = any integer

Output Member	Data Type	Description
EnableOut	BOOL	Enable output.
Dest	DINT	Result of the conversion instruction. Math status flags are set for this output.

Description

BCD is the Binary Coded Decimal number system that expresses individual decimal digits (0-9) in a 4-bit binary notation.

Affects Math Status Flags

Controllers	Affects Math Status Flags
CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers	Conditional, see Math status flags .
CompactLogix 5370, ControlLogix 5570, Compact GuardLogix 5370, and GuardLogix 5570 controllers	Yes

Major/Minor Faults

See Common Attributes
for operand related faults.

A minor fault will occur if:	Fault type	Fault code
feature is enabled and overflow detected and Source < 0	4	4
feature is enabled and overflow detected and Source > 99,999,999 / 9,999, 999,999, 999,999	4	4
feature is enabled and overflow detected	4	4

Execution

Ladder Diagram

Condition/State	Action Taken
Prescan	N/A.
Rung-condition-in is false	N/A.
Rung-condition-in is true	The controller converts the Source to BCD and places the result in the Destination.
Postscan	N/A.

Function Block Diagram

FBD Block

Condition/State	Action Taken
Prescan	N/A
Tag.EnableIn is false.	EnableOut is cleared to false
Tag.EnableIn is true	Dest = the result of computation in BCD value. If overflow occurs Clear EnableOut to false. else Set EnableOut to true.
Instruction first scan	N/A
Instruction first run	N/A
Postscan	N/A

Example

Ladder Diagram

Function Block

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