File Sort (SRT)

This information applies to the

CompactLogix

5370,

ControlLogix

5570,

Compact GuardLogix

5370,

GuardLogix

5570,

CompactLogix

5380,

CompactLogix

5480, and

ControlLogix

5580 controllers. Controller differences are noted where applicable.

The SRT instruction sorts a set of values in one dimension (Dim to vary) of the array into ascending order.

Available Languages

Ladder Diagram

Function Block

This instruction is not available in function block.

Structured Text

SRT(Array,Dimtovary,Control);

Operands

Ladder Diagram

Operand	Type	Format	Description
Array	SINT INT DINT REAL	Array tag	array to sort specify the first element of the group of elements to sort
Dimension to vary	DINT	Immediate (0, 1, 2)	which dimension to use the order of the dimensions is: array[0,1,2]
Control	CONTROL	Tag	control structure for the operation
Length	DINT	Immediate	number of elements of the array to sort
Position	DINT	Immediate	current element in the array initial value is typically 0

Length and Position (corresponding to .LEN and .POS in the control tag) are pseudo-operands. For details, see Pseudo-operand initialization.

Structured Text

Operand	Type	Format	Description
Array	SINT INT DINT REAL	Array tag	array to sort specify the first element of the group of elements to sort
Dimension to vary	DINT	Immediate (0, 1, 2)	which dimension to use the order of the dimensions is: array[0,1,2]
Control	CONTROL	Tag	control structure for the operation
Length	DINT	Immediate	Number of elements of the array to sort. The specified Length and Position values are accessed from the .LEN and .POS members of the CONTROL structure.
Position	DINT	Immediate	current element in the array initial value is typically 0 The specified Length and Position values are accessed from the .LEN and .POS members of the CONTROL structure.

See Structured Text Syntax for more information on the syntax of expressions within structured text.

CONTROL Structure

Mnemonic	Data Type	Description
.EN	BOOL	The enable bit indicates the SRT instruction is enabled.
.DN	BOOL	The done bit is set when the instruction has operated on the last element in the Array.
.ER	BOOL	The error bit is set when either .LEN < 0 or .POS < 0. Either of these conditions also generates a major fault. When .ER bit is set, the instruction does not execute.
.LEN	DINT	The length word specifies the number of elements in the array on which the instruction operates.
.POS	DINT	The position word identifies the current element that the instruction is accessing.

Description

The SRT instruction sorts a set of values in one dimension (Dim to vary) of the Array into ascending order.

IMPORTANT:

You must test and confirm that the instruction does not change data that you don’t want it to change.

The SRT instruction operates on contiguous data memory. For the

CompactLogix

5370,

ControlLogix

5570,

Compact GuardLogix

5370, and

GuardLogix

5570 controllers

only, the scope of the instruction is constrained by the base tag. The SRT instruction will not write data outside of the base tag but can cross member boundaries. If you specify an array that is a member of a structure, and the length exceeds the size of that array you must test and confirm that the SRT instruction does not change data you do not want changed.

In the

CompactLogix

5380,

CompactLogix

5480,

ControlLogix

5580,

Compact GuardLogix

5380, and

GuardLogix

5580 controllers

, the data is constrained by the specified member.

In this transitional instruction, the relay ladder toggles the rung-condition-in from false to true for the instruction to execute.

Affects Math Status Flags

Controllers	Affects Math Status Flags
CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers	No
CompactLogix 5370, ControlLogix 5570, Compact GuardLogix 5370, and GuardLogix 5570 controllers	Yes

Major/Minor Faults

A major fault will occur if:	Fault type	Fault code
.POS < 0 or .LEN < 0	4	21
Dimension to vary > number of dimensions	4	20
Length > end of array	4	20

See Common Attributes
for operand related faults.

Execution

Ladder Diagram

Condition / State	Action Taken
Prescan	N/A.
Rung-condition-in is false	.EN bit is cleared to false .EN bit is cleared to false .DN bit is cleared to false
Rung-condition-in is true	The instruction executes
Postscan	N/A.

Structured Text

Condition / State	Action Taken
Prescan	See Prescan in the Ladder Diagram table
Normal execution	Since this instruction requires a transition to execute it is executed false and then true. See the Ladder Diagram table for details.
Postscan	See Postscan in the Ladder Diagram table.