Sequencer Output (SQO)
This information applies to the
CompactLogix
5370, ControlLogix
5570, Compact GuardLogix
5370, GuardLogix
5570, Compact GuardLogix
5380, CompactLogix
5380, ControlLogix
5580, GuardLogix
5580, and ControlLogix 5590 controllers.TheSQOinstruction sets output conditions for the next step of a sequence pair of SQO/SQI
instructions.
When .EN transitions from false to true, the .POS is incremented. The .POS is reset to 1 when the .POS becomes greater than or equal to .LEN
When .ENis true theSQOinstruction moves the Array data at the .POSthrough the Mask and then
moves the current Destination value through the complemented Mask. The results of those
operations areORedtogether and the result is stored in the Destination.
Available Languages
Ladder Diagram
Operands
The data conversion rules for mixed data types within an instruction. See Data Conversion.
Operand | Type | Format | Description |
|---|---|---|---|
Array | DINT | array tag | Sequencer array Specify the first element of the sequencer array do not use CONTROL.POS in the subscript |
Mask | SINT INT DINT | tag immediate | Used to determine which bits to block (0) or pass (1) and applied during the output masking operation. |
Destination | DINT | tag | Output data from the sequencer array. This value is used in the output masking operation. |
Control | CONTROL | tag | Control structure for the operation The same control tag should be used in the SQI and SQL instructions |
Length | DINT | immediate | Number of elements in the Array (sequencer table) to the output |
Position | DINT | immediate | Current position in the array Initial value is typically 0. |
CONTROL Structure
Mnemonic | Data Type | Description |
|---|---|---|
.EN (Enable) | BOOL | The enable bit indicates the SQO instruction is enabled. |
.DN (Done) | BOOL | The done bit is set when .POS = .LEN |
.ER (Error) | BOOL | Indicates the instruction encountered an error. |
.LEN (Length) | DINT | The length specifies the number of sequencer steps in the sequencer array. |
.POS (Position) | DINT | The position identifies the Array element that the instruction is currently using in the output masking operation. |
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Common Attributes for operand-related faults.
Execution
Ladder Diagram
Condition/State | Action Taken |
|---|---|
Prescan | The .EN is set to true. |
Rung-condition-in is false | The .EN is cleared to false |
Rung-condition-in is true | See the following Flow Chart (True) |
Postscan | N/A |
Flow Chart (True)
Example
The Mask value is AND’d with the array value e.g. Array[SqoControl.POS]. The complement of
the Mask value is AND’d with the currentDestvalue. The results of these two operations are
then OR’d together and the result is stored to theDest.
To reset .POSto the initial value (.POS = 0),us'eaRESinstruction to clear the control
structure. This example uses the status of the first-scan bit to clear the .POSvalue.
Ladder Diagram
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