Rockwell Automation 1756-XXXX ControlLogix Digital I/O Modules - Manual (Page 196)

196 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012
Appendix B Tag Definitions
Pt[x].PWMExtendCycle BOOL Extend PWM Cycle—Determines the output behavior when the value in the
Pt[x]PWMOnTime output tag is less than the value in the Pt[x].PWMMinimunOnTime
configuration tag. Requires PWM to be enabled via the Pt[x].PWMEnable tag.
0 = The duration of the pulse cycle is not extended (default). If the bit is cleared when the
On time is less than the minimum On time, the output is never enabled.
1 = The duration of the pulse cycle is extended to maintain the On time to cycle time ratio
while taking into account the minimum On time.
IMPORTANT: An extension of the pulse cycle is limited to 10 times the cycle time. If the
requested On time is less than 1/10 of the minimum On time, the output will remain Off
and the cycle will not extend. Connection = Data
Output Data = Data or Scheduled
per Module
or
Connection = Peer Ownership
Output Data = Data with Peer
Pt[x].PWMOnTimeInPercent BOOL PWM On Time in Percent—Determines whether PWM On time is defined as a
percentage of the cycle time or is defined in seconds. Requires PWM to be enabled via the
Pt[x].PWMEnable tag.
0 = Defines PWM On time in seconds (default).
1 = Defines PWM On time as a percentage. Connection = Data
Output Data = Data or Scheduled
per Module
or
Connection = Peer Ownership
Output Data = Data with Peer
Pt[x].PWMStaggerOutput BOOL Stagger PWM Outputs—When set, minimizes the load on the power system by
staggering On transitions for outputs. Otherwise, outputs turn On immediately at the start
of a cycle. Requires PWM to be enabled via the Pt[x].PWMEnable tag.
0 = Does not stagger output On transitions (default). Outputs will turn On immediately
when the Pt[x].Data tag is set to 1 beginning the PWM cycle with a rising edge.
1 = Staggers output On transitions. All outputs configured for PWM staggering will turn
On at different intervals to minimize a possible power surge if many outputs became
energized simultaneously. Connection = Data
Output Data = Data or Scheduled
per Module
or
Connection = Peer Ownership
Output Data = Data with Peer
Pt[x].PWMCycleLimitEnable BOOL Enable PWM Cycle Limit—Determines whether to allow only a fixed number of pulse
cycles to occur. Requires PWM to be enabled via the Pt[x].PWMEnable tag.
0 = Pulse cycles continue to occur until the output turns Off (default).
1 = Allows only the number of pulse cycles defined via the Pt[x].PWMCycleLimit tag to
occur. Connection = Data
Output Data = Data or Scheduled
per Module
or
Connection = Peer Ownership
Output Data = Data with Peer
Pt[x].PWMExecuteAllCycles BOOL Execute All PWM Cycles—Determines whether to execute the number of cycles defined
via the Pt[x].PWMCycleLimit tag regardless of the output logic. Requires PWM to be
enabled via the Pt[x].PWMEnable tag, and a cycle limit to be enabled via the
Pt[x].PWMCycleLimitEnable tag.
0 = The output logic determines the number of cycles to produce (default).
1 = The Pt[x].PWMCycleLimit tag determines the number of cycles to produce regardless
of output logic. For example, if you specify a cycle limit of 4, and the output turns Off after
3 cycles, all 4 cycles will still occur despite the output being instructed to turn Off. Connection = Data
Output Data = Data or Scheduled
per Module
or
Connection = Peer Ownership
Output Data = Data with Peer
Pt[x].FaultValueStateDuration SINT Fault State Duration—Defines the length of time that the output state remains in the
Fault mode state before transitioning to a final state of On or Off. The Fault mode state is
defined in the Pt[x].FaultValue tag.
Valid values:
• 0 = Hold forever (default). Output remains in Fault mode for as long as the fault
condition persists.
• 1, 2, 5, or 10 seconds
Connection = Data
Output Data = Data or Scheduled
per Module
or
Connection = Peer Ownership
Output Data = Data with Peer
Pt[x].PWMCycleLimit SINT PWM Cycle Limit—Defines the number of pulse cycles to occur when the output turns
On:
• If the corresponding bit in the Pt[x].PWMExecuteAllCycles tag is set, the configured
number of cycles will occur even if the output turns Off.
• If the corresponding bit in the Pt[x].PWMExecuteAllCycles tag is cleared, the configured
number of cycles will occur only if the output remains On. For example, if the cycle limit
is 4, and the output turns Off after 3 cycles, the 4th cycle will not occur.
The default cycle limit is 10.
Requires PWM to be enabled via the Pt[x].PWMEnable tag, and cycle limits to be enabled
via the Pt[x].PWMCycleLimitEnable tag.
Connection = Data
Output Data = Data or Scheduled
per Module
or
Connection = Peer Ownership
Output Data = Data with Peer
Table 47 - 1756-OB16IEF Module Configuration Tags (continued)
Name Data Type Tag Definition Module Definition