Allen-Bradley LOGIX 5000 Reference Manual page 45

Process Control Instructions
Hand BOOL
Status DINT
InstructFault (Status.0) BOOL
FaultTimeInv (Status.1) BOOL
OperReqInv (Status.2) BOOL
Description
The D2SD instruction controls a discrete device which has only two possible
states (such as on/off or open/closed). Typical discrete devices of this nature
include motors, pumps, and solenoid valves.
Monitoring the D2SD Instruction
There is an operator faceplate available for the D2SD instruction.
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Common Attributes for operand-related
faults.
Execution
Function Block
Condition/State Action Taken
Prescan EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is false EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is true EnableIn and EnableOut bits are set to true.
The instruction executes.
Instruction first run Set ProgOper to Operator Mode. Set CommandStatus to False.
Instruction first scan Set EnableOut to true.
ModeAlarm and operator request inputs are cleared to false,
If ProgValueReset is true, all the program request inputs are cleared to
false.
When OverrideOnInit is true, ProgOper is cleared to false (Operator
control).
If ProgHandReq is cleared and OverrideOnInit is set, clear Hand and set
Override (Override mode).
If ProgHandReq is set, set Hand and clear Override (Hand mode).
Postscan EnableIn and EnableOut bits are cleared to false.
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018
Hand mode. True when the device is in the Hand mode.
Status of the function block.
The instruction detected one of the following execution
errors. This is not a minor or major controller error. Check
the remaining status bits to determine what occurred.
Invalid FaultTime value. The instruction sets FaultTime =
0.
Both operator state request bits are true.
Chapter 1
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