Allen-Bradley Logix5000 Reference Manual

Rockwell Automation Publication 1756-RM003N-EN-P - October 2011 211
Input/Output Instructions (MSG, GSV, SSV, IOT) Chapter 4
WallClockTime Attributes
The WallClockTime object provides a timestamp that the controller can use for
scheduling.
MinimumInterval DINT[2] GSV
SSV
None The minimum time interval between successive executions of the task. DINT[0]
contains the lower 32 bits of the value; DINT[1] contains the upper 32 bits of the
value. A value of 0 indicates 1 or less executions of the task.
Name String GSV GSV Name of the task.
OverlapCount DINT GSV
SSV
GSV
SSV
Number of times that the task was triggered while it was still executing. Valid for
an event or a periodic task. To clear the count, set the attribute to 0.
Priority INT GSV
SSV
GSV Relative priority of this task as compared to the other tasks. Valid values 0...15.
Rate DINT GSV
SSV
GSV The time interval between executions of the task. Time is in microseconds.
StartTime DINT[2] GSV
SSV
None Value of WALLCLOCKTIME when the last execution of the task was started.
DINT[0] contains the lower 32 bits of the value; DINT[1] contains the upper 32
bits of the value.
Status DINT GSV
SSV
None Status information about the task. Once the controller sets one of these bits, you
must manually clear the bit.
Bit Meaning
0 An EVENT instruction triggered the task (event task only)
1 A timeout triggered the task (event task only)
2 An overlap occurred for this task
Watchdog DINT GSV
SSV
GSV Time limit for execution of all programs associated with this task. Time is in
microseconds.
If you enter 0, these values are assigned:
Time Task Type
0.5 sec Periodic
5.0 sec Continuous
Attribute Data Type Instruction
within
Standard
Task
Instruction
within
Safety Task
Description
Attribute Data Type Instruction Description
ApplyDST SINT GSV
SSV
Identifies whether to enable daylight savings time.
Value Meaning
0 Do not adjust for daylight savings time
non zero Adjust for daylight savings time
CSTOffset DINT[2] GSV
SSV
Positive offset from the CurrentValue of the CST object (coordinated system time, see
page 202
). DINT[0] contains the lower 32 bits of the value; DINT[1] contains the upper
32 bits of the value. Value in μ s. The default is 0.
CurrentValue DINT[2] GSV
SSV
Current value of the wall clock time. DINT[0] contains the lower 32 bits of the value;
DINT[1] contains the upper 32 bits of the value. The value is the number of
microseconds that have elapsed since 0000 hours 1 January 1972. The CST and
WALLCLOCKTIME objects are mathematically related in the controller. For example, if
you add the CST CurrentValue and the WALLCLOCKTIME CTSOffset, the result is the
WALLCLOCKTIME CurrentValue.

Allen-Bradley Logix5000 Specifications

General

Brand	Allen-Bradley
Model	Logix5000
Category	Controller
Language	English