Process Lead Lag Standby Motor Group (PLLS)

This information applies to the CompactLogix 5380P and ControlLogix 5580P controllers.
The Process Lead Lag Standby Motor Group (PLLS) instruction provides control of a parallel group of motors, such as a set of pumps with a common intake source and discharge destination. The number of motors to run depends on the demand on the system. The group can be configured to consist of as few as two or as many as 30 motors. The minimum demand can be set as low as 0, so that all motors are stopped at minimum demand. The maximum demand can be set as high as the number of pumps in the group.
Use the PLLS instruction to:
  • Control and monitor a group of 2 to 30 motors.
  • Start and stop a group using Operator, Program, and Override capability.
  • Allow the Operator or Program to enter a demand (the number of motors to run).
  • Configure maximum demand (1 to number of motors in group).
  • Configure minimum demand (0 to maximum demand).
  • Configure stopping the last started motor or the first started motor (first-on-last-off or last-on-last-off).
  • Configure delay between starts and configure delay between stops.
  • Use start and stop commands to start or stop the motors as a group. The delay between starts or stops can be configured to sequence the motors.
  • Start or stop motors as required to meet the entered demand.
  • Identify (and optionally alarm) when there are not enough motors available to start (in Program Mode and ready to run) to meet the given demand.
  • Identify (and optionally alarm) when there are not enough motors available to stop (in Program Mode and ready to stop) to meet the given demand.
  • Ability to rotate the list of motors (demote the lead, promote the others).
  • Monitor Permissive conditions to allow starting the motor group.
  • Monitor Interlock conditions to stop or prevent starting the motor group.
  • Alarm if interlock conditions cause the group to be stopped.
  • Use HMI breadcrumbs for Alarm Inhibited, Bad Configuration, Not Ready, and Maintenance Bypass Active.
  • Use Available status in automation logic to determine whether the motor group can be controlled by other objects.
Available Languages
Ladder Diagram
PLLS_available_ladder
Function Block Diagram
PLLS_available_FBD
Structured Text
PLLS (PLLS tag, Ref_Motors tag, BusObj tag);
Operands
IMPORTANT:
Unexpected operation may occur if:
  • Output tag operands are overwritten.
  • Members of a structure operand are overwritten.
  • Except when specified, structure operands are shared by multiple instructions.
There are data conversion rules for mixing numeric data types within an instruction. See Data conversions.
Configuration Operands
This table describes the PLLS configuration operands.
Operand
Type
Format
Description
PlantPAx Control
P_LEAD_LAG_STANDBY
tag
Data structure required for proper operation of instruction.
Ref_Motors
P_LEAD_LAG_STANDBY_MOTOR
tag
Motor interface array.
BusObj
BUS_OBJ
tag
Bus component.
P_LEAD_LAG_STANDBY Structure
Use InOut parameters to link the instruction to external tags that contain necessary data for the instruction to operate. These external tags must be of the data type shown.
Public members are standard, visible tag members that are programmatically accessible. Private, hidden members are used in HMI faceplates and are not programmatically accessible. Private members are listed in separate tables after public members.
Public Input Members
Data Type
FBD Default Visibility
FBD Wiring required
Usage
Description
EnableIn
BOOL
Not Visible
Not Required
Input
Enable Input. Ladder Diagram. Corresponds to the rung-condition-in.
Default is true.
Inp_InitializeReq
BOOL
Not Visible
Not Required
Input
1 = Request to initialize the instruction. The instruction is normally initialized in instruction first run. Use this request when reinitialization is needed. The instruction clears this operand automatically.
Default is true.
Inp_OwnerCmd
DINT
Not Visible
Not Required
Input
Owner device command. 0 = None, Inp_OwnerCmd.10 = Operator Lock, Inp_OwnerCmd.11 = Operator Unlock, Inp_OwnerCmd.12 = Program Lock, Inp_OwnerCmd.13 = Program Unlock, Inp_OwnerCmd.14 = Acquire Maintenance,
Inp_OwnerCmd.15 = Release Maintenance,
Inp_OwnerCmd.16 = Acquire External, Inp_OwnerCmd.17 = Release External.
Default is 0.
Inp_PermOK
BOOL
Visible
Not Required
Input
1 = Start permissives OK, group can start.
Default is true.
Inp_NBPermOK
BOOL
Visible
Not Required
Input
1 = Non-bypassable start permissives OK, group can start.
Default is true.
Inp_IntlkOK
BOOL
Visible
Not Required
Input
1 = Interlocks OK, group can start/run.
Default is true.
Inp_NBIntlkOK
BOOL
Visible
Not Required
Input
1 = Non-bypassable interlocks OK, group can start/run.
Default is true.
Inp_IntlkAvailable
BOOL
Visible
Not Required
Input
1 = Interlock availability OK.
Default is false.
Inp_IntlkTripInh
BOOL
Visible
Not Required
Input
1 = Inhibit interlock trip status.
Default is false.
Inp_RdyReset
BOOL
Visible
Not Required
Input
1 = Related object, reset by this object, is ready to be reset.
Default is false.
Inp_Hand
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Inp_Ovrd
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Inp_OvrdDemand
DINT
Visible
Not Required
Input
Override Mode setting for number of motors to run (MinDemand..MaxDemand).
Default is 0.
Inp_OvrdCmd
DINT
Visible
Not Required
Input
Override Mode Command: 0 = None, 1 = Stop Group, 2 = Start Group, 3 = Rotate Assignments.
Default is 0.
Inp_ExtInh
BOOL
Visible
Not Required
Input
Control / command source selection.
Default is false.
Inp_Reset
BOOL
Not Visible
Not Required
Input
1 = Reset all fault conditions and latched alarms.
Default is false.
Cfg_AllowDisable
BOOL
Not Visible
Not Required
Input
1 = Allow maintenance to disable alarms.
Default is true.
Cfg_AllowShelve
BOOL
Not Visible
Not Required
Input
1 = Allow operator to shelve alarms.
Default is true.
Cfg_NumMotors
DINT
Not Visible
Not Required
Input
Number of motors in this Lead / Lag / Standby Group. Valid = 2 to 30.
Default is 3.
Cfg_MaxDemand
DINT
Not Visible
Not Required
Input
Maximum number of motors to run. Valid = 1 to Cfg_NumMotors.
Default is 2.
Cfg_MinDemand
DINT
Not Visible
Not Required
Input
Minimum number of motors to run. Valid = 0 to Cfg_MaxDemand.
Default is 0.
Cfg_StartDly
REAL
Not Visible
Not Required
Input
Time (seconds) after start or stop until next start is allowed (0..2M seconds). Valid = 0.0 to 2147483.0.
Default is 10.0.
Cfg_StopDly
REAL
Not Visible
Not Required
Input
Time (seconds) after start or stop until next stop is allowed (0..2M seconds). Valid = 0.0 to 2147483.0.
Default is 10.0.
Cfg_FirstOnFirstOff
BOOL
Not Visible
Not Required
Input
1 = First started is first stopped, 0 = First started is last stopped.
Default is false.
Cfg_AllowRotate
BOOL
Not Visible
Not Required
Input
1 = Allow rotate (cycle lead) command to rotate motor assignments.
Default is true.
Cfg_RotateOnStop
BOOL
Not Visible
Not Required
Input
1 = Rotate (cycle lead to end of list) upon stopping all motors.
Default is true.
Cfg_HasPermObj
BOOL
Not Visible
Not Required
Input
1 = Tells HMI an object is connected to permissive inputs.
Default is false.
Cfg_HasIntlkObj
BOOL
Not Visible
Not Required
Input
1 = Tells HMI an object is connected to interlock inputs.
Default is false.
Cfg_HasMoreObj
BOOL
Not Visible
Not Required
Input
1 = Tells HMI an object with more information is available.
Default is false.
Cfg_HasNav01
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #1.
Default is false.
Cfg_HasNav02
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #2.
Default is false.
Cfg_HasNav03
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #3.
Default is false.
Cfg_HasNav04
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #4.
Default is false.
Cfg_HasNav05
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #5.
Default is false.
Cfg_HasNav06
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #6.
Default is false.
Cfg_HasNav07
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #7.
Default is false.
Cfg_HasNav08
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #8.
Default is false.
Cfg_HasNav09
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #9.
Default is false.
Cfg_HasNav10
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #10.
Default is false.
Cfg_HasNav11
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #11.
Default is false.
Cfg_HasNav12
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #12.
Default is false.
Cfg_HasNav13
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #13.
Default is false.
Cfg_HasNav14
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #14.
Default is false.
Cfg_HasNav15
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #15.
Default is false.
Cfg_HasNav16
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #16.
Default is false.
Cfg_HasNav17
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #17.
Default is false.
Cfg_HasNav18
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #18.
Default is false.
Cfg_HasNav19
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #19.
Default is false.
Cfg_HasNav20
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #20.
Default is false.
Cfg_HasNav21
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #21.
Default is false.
Cfg_HasNav22
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #22.
Default is false.
Cfg_HasNav23
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #23.
Default is false.
Cfg_HasNav24
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #24.
Default is false.
Cfg_HasNav25
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #25.
Default is false.
Cfg_HasNav26
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #26.
Default is false.
Cfg_HasNav27
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #27.
Default is false.
Cfg_HasNav28
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #28.
Default is false.
Cfg_HasNav29
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #29.
Default is false.
Cfg_HasNav30
BOOL
Not Visible
Not Required
Input
1 = enable a button on the HMI that is used to call up the faceplate for motor #30.
Default is false.
Cfg_SetTrack
BOOL
Not Visible
Not Required
Input
1 = When the owner is program the operator settings track the program settings. When the owner is operator the program settings track the operator settings, and the virtual inputs match the output values (transitions are bumpless), 0 = No tracking.
Default is false.
Cfg_SetTrackOvrdHand
BOOL
Not Visible
Not Required
Input
1 = program/operator settings track override/hand speed reference.
Default is false.
Cfg_OperStopPrio
BOOL
Not Visible
Not Required
Input
1 = OCmd_Stop any time, 0 = OCmd_Stop only when operator selected.
Default is false.
Cfg_ExtStopPrio
BOOL
Not Visible
Not Required
Input
1 = XCmd_Stop any time, 0 = XCmd_Stop only when external selected.
Default is false.
Cfg_OCmdResets
BOOL
Not Visible
Not Required
Input
1 = New group OCmd resets shed latches and cleared alarms, 0 = OCmdReset required.
Default is false.
Cfg_XCmdResets
BOOL
Not Visible
Not Required
Input
1 = New group XCmd resets shed latches and cleared alarms, 0 = OCmdReset required.
Default is false.
Cfg_OvrdPermIntlk
BOOL
Not Visible
Not Required
Input
1 = Override ignores bypassable permissives/interlocks, 0 = Always use permissives/interlocks.
Default is false.
Cfg_CnfrmReqd
SINT
Not Visible
Not Required
Input
Operator command confirmation required. Represents the type of command confirmation required.
0 = None,
1 = Command confirmation required,
2 = Performer e-signature required,
3 = Performer and approver e-signature required.
Default is 0.
PSet_Demand
DINT
Not Visible
Not Required
Input
Program setting for number of motors to run (MinDemand...MaxDemand).
Default is 0.
PSet_Owner
DINT
Not Visible
Not Required
Input
Program owner request ID (non-zero) or release (zero).
Default is 0.
XSet_Demand
DINT
Not Visible
Not Required
Input
External setting for number of motors to run (MinDemand...MaxDemand).
Default is 0.
PCmd_Start
BOOL
Not Visible
Not Required
Input
Program command to start motor group.
Default is false.
PCmd_Stop
BOOL
Not Visible
Not Required
Input
Program command to stop motor group.
Default is false.
PCmd_Rotate
BOOL
Not Visible
Not Required
Input
Program command to rotate assignments (cycle lead to end of list).
Default is false.
PCmd_Prog
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
PCmd_Oper
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
PCmd_Lock
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
PCmd_Unlock
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
PCmd_Normal
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
PCmd_Reset
BOOL
Not Visible
Not Required
Input
Program command to reset all alarms requiring reset.
Default is false.
XCmd_Start
BOOL
Not Visible
Not Required
Input
External command to start motor group.
Default is false.
XCmd_Stop
BOOL
Not Visible
Not Required
Input
External command to stop motor group.
Default is false.
XCmd_Rotate
BOOL
Not Visible
Not Required
Input
External command to rotate assignments (cycle lead to end of list).
Default is false.
XCmd_Reset
BOOL
Not Visible
Not Required
Input
External command to reset all alarms requiring reset. The instruction clears this operand automatically.
Default is false.
XCmd_ResetAckAll
BOOL
Not Visible
Not Required
Input
External command to acknowledge and reset all alarms and latched shed conditions. The instruction clears this operand automatically.
Default is false.
Cfg_HasOper
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is true.
Cfg_HasOperLocked
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is true.
Cfg_HasProg
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is true.
Cfg_HasProgLocked
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is true.
Cfg_HasExt
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Cfg_HasMaint
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is true.
Cfg_HasMaintOoS
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is true.
Cfg_OvrdOverLock
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is true.
Cfg_ExtOverLock
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Cfg_ProgPwrUp
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Cfg_ProgNormal
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Cfg_PCmdPriority
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Cfg_PCmdProgAsLevel
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Cfg_PCmdLockAsLevel
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Cfg_ExtAcqAsLevel
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
XCmd_Acq
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
XCmd_Rel
BOOL
Not Visible
Not Required
Input
Control / command source selection.
Default is false.
Public Output Members
Data Type
FBD Default Visibility
FBD Wiring required
Usage
Description
EnableOut
BOOL
Not Visible
Not Required
Output
Enable Output. This output state always reflects EnableIn input state.
Val_Demand
DINT
Visible
Not Required
Output
Number of motors requested to run.
Val_RotateRank
DINT
Not Visible
Not Required
Output
Motor rank (0 = Lead, etc.) which will be demoted on rotate.
Val_RotateID
DINT
Not Visible
Not Required
Output
Motor number which will be demoted on rotate.
Sts_eCmd
SINT
Not Visible
Not Required
Output
Group command 0 = None, 1 = Stop, 2 = Start.
Sts_Fdbk
SINT
Not Visible
Not Required
Output
Group Feedback 0...31 = Number of motors actually running.
Sts_eSts
INT
Not Visible
Not Required
Output
Group confirmed status: 0 = ?,
1 = Stopped,
2 = Running,
3 = Stopping,
4 = Decreasing,
5 = Increasing.
Sts_eFault
INT
Not Visible
Not Required
Output
Group fault status:
0 = None,
1 = Configuration error,
12 = Fail to start,
13 = Fail to stop.
Sts_eNotifyAll
SINT
Not Visible
Not Required
Output
Highest alarm priority and acknowledge status this object + motors (enumeration).
Sts_Initialized
BOOL
Not Visible
Not Required
Output
1 = Instruction is initialized. Use Inp_InitializeReq to reinitialize.
Sts_Stopped
BOOL
Visible
Not Required
Output
1 = Motor group requested to stop and all motors confirmed stopped.
Sts_Running
BOOL
Visible
Not Required
Output
1 = Motor group requested to run.
Sts_Stopping
BOOL
Visible
Not Required
Output
1 = Motor group requested to stop and not all motors confirmed stopped.
Sts_Incr
BOOL
Visible
Not Required
Output
1 = Group is starting motors in sequence to get up to demand.
Sts_Decr
BOOL
Visible
Not Required
Output
1 = Group is stopping motors in sequence to get down to demand.
Sts_Available
BOOL
Not Visible
Not Required
Output
1 = Group available for control by automation (program).
Sts_IntlkAvailable
BOOL
Not Visible
Not Required
Output
1 = Device can be acquired by program and is available for start/stop control when interlocks are OK.
Sts_Bypass
BOOL
Not Visible
Not Required
Output
1 = Bypassable interlocks and permissives are bypassed.
Sts_BypActive
BOOL
Not Visible
Not Required
Output
1 = Interlock bypassing active (bypassed or maintenance).
Sts_NotRdy
BOOL
Not Visible
Not Required
Output
1 = Group is not ready, for HMI use hidden detail bits (Sts_Nrdyxxx) for reason.
Sts_NrdyCfgErr
BOOL
Not Visible
Not Required
Output
1 = Group is not ready: Configuration error.
Sts_NrdyIntlk
BOOL
Not Visible
Not Required
Output
1 = Group is not ready: Interlock not OK.
Sts_NrdyOoS
BOOL
Not Visible
Not Required
Output
1 = Group is not ready: Group is out of service.
Sts_NrdyPrioStop
BOOL
Not Visible
Not Required
Output
1 = Group is not ready: Operator/external priority stop requires reset.
Sts_NrdyPerm
BOOL
Not Visible
Not Required
Output
1 = Group is not ready: Permissive not OK.
Sts_MaintByp
BOOL
Not Visible
Not Required
Output
1 = A maintenance bypass function is active.
Sts_Alm
BOOL
Not Visible
Not Required
Output
1 = An alarm is active.
Sts_AlmInh
BOOL
Not Visible
Not Required
Output
1 = One or more alarms shelved, disabled, or suppressed.
Sts_Err
BOOL
Visible
Not Required
Output
1 = Error in configuration: See detail bits (Sts_Errxxx) for reason.
Sts_ErrStartDly
BOOL
Not Visible
Not Required
Output
1 = Error in configuration: Start check timer preset (use 0.0 to 2147483.0).
Sts_ErrStopDly
BOOL
Not Visible
Not Required
Output
1 = Error in configuration: Stop check timer preset (use 0.0 to 2147483.0).
Sts_ErrAlm
BOOL
Not Visible
Not Required
Output
1 = Error in configuration: Alarm throttle time or severity.
Val_Owner
DINT
Not Visible
Not Required
Output
Current object owner ID (0 = not owned).
Sts_MotorAvailable
DINT
Not Visible
Not Required
Output
Set bits indicate which motors are available for program control.
Sts_MotorStopped
DINT
Not Visible
Not Required
Output
Set bits indicate which motors are confirmed stopped.
Sts_MotorStarting
DINT
Not Visible
Not Required
Output
Set bits indicate which motors are starting.
Sts_MotorRunning
DINT
Not Visible
Not Required
Output
Set bits indicate which motors are confirmed running.
Sts_MotorStopping
DINT
Not Visible
Not Required
Output
Set bits indicate which motors are confirmed stopped.
Sts_Hand
BOOL
Visible
Not Required
Output
Control / command source selection.
Sts_OoS
BOOL
Visible
Not Required
Output
Control / command source selection.
Sts_Maint
BOOL
Visible
Not Required
Output
Control / command source selection.
Sts_Ovrd
BOOL
Visible
Not Required
Output
Control / command source selection.
Sts_Ext
BOOL
Visible
Not Required
Output
Control / command source selection.
Sts_Prog
BOOL
Visible
Not Required
Output
Control / command source selection.
Sts_ProgLocked
BOOL
Not Visible
Not Required
Output
Control / command source selection.
Sts_Oper
BOOL
Visible
Not Required
Output
Control / command source selection.
Sts_OperLocked
BOOL
Not Visible
Not Required
Output
Control / command source selection.
Sts_Normal
BOOL
Not Visible
Not Required
Output
Control / command source selection.
Sts_ExtReqInh
BOOL
Not Visible
Not Required
Output
Control / command source selection.
Sts_ProgReqInh
BOOL
Not Visible
Not Required
Output
Control / command source selection.
Sts_MAcqRcvd
BOOL
Not Visible
Not Required
Output
Control / command source selection.
Sts_CantStart
BOOL
Not Visible
Not Required
Output
1 = Motor failed to start (one-shot).
Sts_CantStop
BOOL
Not Visible
Not Required
Output
1 = Motor failed to stop.
Sts_IntlkTrip
BOOL
Not Visible
Not Required
Output
1 = Group stopped by an interlock NOT OK (one-shot).
Sts_RdyReset
BOOL
Not Visible
Not Required
Output
1 = A latched alarm or shed condition is ready to be reset.
Sts_RdyAck
BOOL
Not Visible
Not Required
Output
1 = An alarm is ready to be acknowledged.
Sts_UnackAlmCount
DINT
Not Visible
Not Required
Output
Count of unacknowledged alarms.
Out_Reset
BOOL
Not Visible
Not Required
Output
1 = Reset command has been received and accepted.
Out_OwnerSts
DINT
Not Visible
Not Required
Output
Status of command source, owner command handshake and ready status. 0 = None,
.10 = Operator Lock,
.11 = Operator Unlock,
.12 = Program Lock,
.13 = Program Unlock,
.14 = Acquire Maintenance,
.15 = Release Maintenance,
.16 = Acquire External,
.17 = Release External,
.18 = Has Maintenance,
.19 = External Override Lock,
.20 = Has External,
.21 = Has Operator,
.22 = Has Program,
.30 = Not Ready.
Sts_eSrc
INT
Not Visible
Not Required
Output
The current command source enumerated values:
0 = Logic not in use,
4 = Hand,
8 = Maintenance,
16 = Override,
32 = Program,
33 = Program locked,
34 = Program by default (Normal),
64 = Operator,
65 = Operator locked,
66 = Operator by default (Normal),
128 = Maintenance Out of Service,
129 = Programmed Out of Service (rung false),
256 = External.
Sts_bSrc
INT
Not Visible
Not Required
Output
Control / command source selection.
Sts_ProgOperSel
BOOL
Not Visible
Not Required
Output
Control / command source selection.
Sts_ProgOperLock
BOOL
Visible
Not Required
Output
Control / command source selection.
XRdy_Acq
BOOL
Not Visible
Not Required
Output
Control / command source selection.
XRdy_Rel
BOOL
Not Visible
Not Required
Output
Control / command source selection.
XRdy_Reset
BOOL
Not Visible
Not Required
Output
1 = Ready for XCmd_Reset, enable HMI button.
XRdy_ResetAckAll
BOOL
Not Visible
Not Required
Output
1 = Ready for XCmd_ResetAckAll, enable HMI button.
XRdy_Stop
BOOL
Not Visible
Not Required
Output
1 = Ready for XCmd_Stop, enable HMI button.
XRdy_Start
BOOL
Not Visible
Not Required
Output
1 = Ready for XCmd_Start, enable HMI button.
XRdy_Rotate
BOOL
Not Visible
Not Required
Output
1 = Ready for XCmd_Rotate, enable HMI button.
Private Input Members
Data Type
Description
CmdSrc
P_COMMAND_SOURCE
Control or Command Source Selection.
MCmd_Acq
BOOL
Maintenance command to acquire ownership (Operator/Program/External/Override to Maintenance). The instruction clears this operand automatically.
Default is false.
MCmd_Bypass
BOOL
Maintenance command to bypass all bypassable interlocks and permissives.
Default is false.
MCmd_Check
BOOL
Maintenance command to check (not bypass) all interlocks and permissives.
Default is false.
MCmd_IS
BOOL
Maintenance command to select In Service. The instruction clears this operand automatically.
Default is false.
MCmd_OoS
BOOL
Maintenance command to select Out of Service. The instruction clears this operand automatically.
Default is false.
MCmd_Rel
BOOL
Maintenance command to release ownership (Maintenance to Operator/Program/External/Override). The instruction clears this operand automatically.
Default is false.
MSet_MotorOoS
DINT
Set bits indicate which motors have been taken out of service by maintenance.
Default is 2#0000_0000_0000_0000_0000_0000_0000_0000.
OCmd_CmdCncl
BOOL
Operator command to cancel command request. The instruction clears this operand automatically.
Default is false.
OCmd_Lock
BOOL
Operator command to lock Operator (disallow Program). The instruction clears this operand automatically.
Default is false.
OCmd_Normal
BOOL
Operator command to select Normal (Operator or Program). The instruction clears this operand automatically.
Default is false.
OCmd_Oper
BOOL
Operator command to select Operator (Program to Operator). The instruction clears this operand automatically.
Default is false.
OCmd_Prog
BOOL
Operator command to select Program (Operator to Program). The instruction clears this operand automatically.
Default is false.
OCmd_Reset
BOOL
Operator command to reset all alarms requiring reset.
Default is false.
OCmd_ResetAckAll
BOOL
Operator command to reset all alarms and latched shed conditions.
Default is false.
OCmd_ResetPrefs
BOOL
Operator command to reset all motor preferences to 0.
Default is false.
OCmd_Rotate
BOOL
Operator command to rotate assignments (cycle lead to end of list).
Default is false.
OCmd_SetPrefs
BOOL
Operator command to set motor preferences.
Default is false.
OCmd_Start
BOOL
Operator command to start motor group.
Default is false.
OCmd_Stop
BOOL
Operator command to stop motor group.
Default is false.
OCmd_Unlock
BOOL
Operator command to unlock / release (allow Program to acquire) ownership. The instruction clears this operand automatically.
Default is false.
OSet_Demand
DINT
Operator setting for number of motors to run (MinDemand.. MaxDemand).
Default is 0.
Private Output Members
Data Type
Description
HMI_BusObjIndex
DINT
HMI bus object index.
Default is 0.
MRdy_Acq
BOOL
1 = Ready for MCmd_Acq, enable HMI button.
MRdy_Bypass
BOOL
1 = Ready for MCmd_Bypass (enables HMI button).
MRdy_Check
BOOL
1 = Ready for MCmd_Check (enables HMI button).
MRdy_IS
BOOL
1 = Ready for MCmd_IS, enable HMI button.
MRdy_OoS
BOOL
1 = Ready for MCmd_OoS, enable HMI button.
MRdy_Rel
BOOL
1 = Ready for MCmd_Rel, enable HMI button.
ORdy_Demand
BOOL
1 = Ready for OSet_Demand (enables numeric entry).
ORdy_Lock
BOOL
1 = Ready for OCmd_Lock, enable HMI button.
ORdy_Normal
BOOL
1 = Ready for OCmd_Normal, enable HMI button.
ORdy_Oper
BOOL
1 = Ready for OCmd_Oper, enable HMI button.
ORdy_Prog
BOOL
1 = Ready for OCmd_Prog, enable HMI button.
ORdy_Reset
BOOL
1 = Ready for OCmd_Reset (enables HMI button).
ORdy_ResetAckAll
BOOL
1 = Ready for OCmd_ResetAckAll (enables HMI button).
ORdy_Rotate
BOOL
1 = Ready for OCmd_Rotate (enables HMI button).
ORdy_Start
BOOL
1 = Ready for OCmd_Start (enables HMI button).
ORdy_Stop
BOOL
1 = Ready for OCmd_Stop (enables HMI button).
ORdy_Unlock
BOOL
1 = Ready for OCmd_Unlock, enable HMI button.
Sts_bStsList
SINT[32]
Rank list of motor status:
[0]=lead,
[1]=lag, etc.;
.0 = Avaiable,
.1 = Stopped,
.2 = Starting,
.3 = Running,
.4 = Stopping,
.5 = Out of Service (Maint).
Sts_eNotify
SINT
Current alarm level and acknowledgement (enumeration).
Sts_eNotifyCantStart
SINT
Current alarm level and acknowledgement (enumeration).
Sts_eNotifyCantStop
SINT
Current alarm level and acknowledgement (enumeration).
Sts_eNotifyIntlkTrip
SINT
Current alarm level and acknowledgement (enumeration).
Val_PrefList
SINT[32]
Rank list of motor preferences: [0] = lead, [1] = lag, etc...
Val_PrioList
SINT[32]
Rank list of motor priorities: [0] = lead, [1] = lag, etc...
Val_RankList
SINT[32]
Rank list of motor numbers: [0] = lead, [1] = lag, etc...
Val_UsrList
INT[32]
Rank list of user sort criteria: [0] = lead, [1] = lag, etc...
Public InOut Members
Data Type
FBD Default Visibility
FBD Wiring required
Usage
Description
Ref_Motors
P_LEAD_LAG_STANDBY_MOTOR[30]
Visible
Required
InOut
Motor interface array (link to 2 to 30 motors).
BusObj
BUS_OBJ
Visible
Optional
InOut
Bus component.
Alarms
Discrete tag-based alarms are defined for these members.
Member
Alarm Name
Description
Sts_CantStart
Alm_CantStart
Motor can’t start alarm.
Raised when there are not enough motors available to start to satisfy the entered demand. Too many motors are faulted or stopped in a mode other than program.
Sts_CantStop
Alm_CantStop
Motor can’t stop alarm.
Raised when there are not enough motors available to stop to satisfy the entered demand. Too many motors are running in a mode other than program.
Sts_IntlkTrip
Alm_IntlkTrip
Interlock Trip alarm.
Raised when the motor is running and an interlock not-OK condition causes the motor to stop.
If interlocks are not bypassed, a bypassable interlock or a non-bypassable interlock not-OK condition initiates an interlock trip. If interlocks are bypassed, only a non-bypassable interlock not-OK condition initiates an interlock trip.
Mark an alarm as used or unused and set standard configuration members of the discrete tag-based alarm. Use this format to access alarm elements:
Tag.@Alarms.AlarmName.AlarmElement
There are Program commands for each Alarm that are available to Acknowledge, Suppress, Unsupress and Unshelve the Alarm. These commands are propagated to corresponding commands (ProgAck, ProgSuppress, ProgUnsupress, ProgUnshelve) of the tag-based alarm.
There are Program, Operator, and External commands available that Acknowledge, Reset, Suppress and Unsuppress all alarms of the instruction (Alarm Set) at the same time.
PLLS_alarmfunction
Operation
This diagram illustrates the functionality of the PLLS instruction:
PLLS_Operation_v34
Configuration of Strings for HMI
Configure strings for HMI faceplates (
FactoryTalk View
) and for the
Logix Designer
 configuration dialog box. The strings are set to extended properties of tag items.
  • Description
  • Label for graphic symbol
  • Display Library for HMI Faceplate call-up
  • Instruction name
  • Area name
  • URL link
  • More Information
Implementation
An operator or other logic determines the demand for motors. The PLLS instruction determines which motors to run to meet demand. For the PLLS instruction to start and stop motors in the group, they must be available. A motor is available when it has no faults and is in Program Mode.
The PLLS instruction uses a sorting algorithm to deal with motors that are not available. If a motor is running and not available (perhaps running in Operator Mode), the motor is forced to the top of the sort. If a motor is stopped and not available (perhaps faulted), the motor is forced to the bottom of the sort. The motors that are available to start and stop are controlled to meet the demand. If the demand cannot be met because of unavailable motors, a status/alarm is provided.
The PLLS instruction uses an array of structures of the type P_LEAD_LAG_STANDBY_Motor to interface to the motors. Each interface element in the array provides the signals that are required between the PLLS instruction and one motor. Configuration data for the motor is also provided in the array. This data includes Priority and Preference values that can be used to affect the sorting of the motors. A Maintenance out of service flag that removes a motor from consideration in the sort is also included. The interface also includes a user sort value that can be used, for example, to push motors up or down the sort based on accumulated runtime or other criteria.
P_LEAD_LAG_STANDBY_MOTOR Array Member Content
This table describes the array members.
Members
Data Type
Description
Inp_OtherSel
DINT
Other motor selection criteria (0...255) (input to PLLS).
Inp_Demote
BOOL
Demote this motor to bottom of list (for example, on high runtime) (input to PLLS).
Cfg_Prio
DINT
Motor priority in list (0...31 -- if unused, set to 0).
OSet_Pref
DINT
Operator setting for motor preference in list (0 to 31), all else being equal.
PCmd_Start
BOOL
Program Command to start motor (output from PLLS).
PCmd_Stop
BOOL
Program Command to stop motor (output from PLLS).
PCmd_Lock
BOOL
Command to acquire and lock motor in Program (output from PLLS).
PCmd_Unlock
BOOL
Command to unlock motor from Program (output from PLLS).
Sts_Available
BOOL
Motor is in Program mode and ready to operate (input to PLLS).
Sts_Stopped
BOOL
Motor is currently confirmed stopped (input to PLLS).
Sts_Starting
BOOL
Motor is currently starting (input to PLLS).
Sts_Running
BOOL
Motor is currently confirmed running (input to PLLS).
Sts_Stopping
BOOL
Motor is currently stopping (input to PLLS).
Val_Pref
DINT
This motor’s current preference in list (1 = Lead, 2 = Lag, …).
Val_Rank
DINT
This motor’s current rank in list (1 = Lead, 2 = Lag, …)
This image shows the relationship between the PLLS instruction, Ref_Motors(interface), and the PMTR instruction.
PLLS_PMTR_relationship
These images show an example of the ladder logic for transferring commands and motor status for one motor.
The process for forwarding each of the commands (PCmd_Lock, PCmd_Unlock, PCmd_Start, and PCmd_Stop) is:
  • Test the appropriate bit in the interface to see if it is set.
  • If the bit is set, the bit is cleared and the corresponding program command on the motor is set.
PLLS_transfercommands1
  • Execute the PLLS to select which motors to run.
PLLS_transfercommands2
  • Next, the motor logic is executed. The motor logic uses the program commands to control the physical motor. The motor logic also receives feedback from the motor.
PLLS_transfercommands3
  • The status (available, stopped, starting, running, and stopping) is read from the motor and written to the interface.
PLLS_transfercommands4
Monitor the PLLS Instruction
Use the operator faceplate from the PlantPAx library of Process objects for monitoring.
Affects Math Status Flags
No.
Major/Minor Faults
None specific to this instruction. See Index Through Arrays for array-indexing faults.
Execution
Ladder Diagram
Condition/State
Action Taken
Prescan
Any commands received before first scan are discarded. The motor is de-energized and treated as if it were commanded to stop.
Instruction first run
Any commands received before first scan are discarded. The motor is de-energized and treated as if it were commanded to stop.
Rung-condition-in is false
Handled the same as if the group is disabled by command. The motor outputs are de-energized, and the group is shown as disabled on the HMI. The mode is shown as No mode. All alarms are cleared.
Rung-condition-in is true
Set rung-condition-out to rung-condition-in.
The instruction executes.
Postscan
Rung-condition-out is cleared to false.
Function Block Diagram
Condition/State
Action Taken
Prescan
Any commands received before first scan are discarded. The motor is de-energized and treated as if it were commanded to stop.
Instruction first run
Any commands received before first scan are discarded. The motor is de-energized and treated as if it were commanded to stop.
Instruction first scan
See instruction first run in the function block diagram table.
EnableIn is false
Handled the same as if the group is disabled by command. The motor outputs are de-energized, and the group is shown as disabled on the HMI. The mode is shown as No mode. All alarms are cleared.
EnableIn is true
EnableOut is set to true.
The instruction executes.
Postscan
EnableIn and EnableOut bits are cleared to false.
Structured Text
In Structured Text, EnableIn is always true during normal scan. Therefore, if the instruction is in the control path activated by the logic it will execute.
Condition/State
Action Taken
Prescan
Any commands received before first scan are discarded. The motor is de-energized and treated as if it were commanded to stop.
Instruction first run
Any commands received before first scan are discarded. The motor is de-energized and treated as if it were commanded to stop.
EnableIn is true
EnableOut is set to true.
The instruction executes.
Postscan
EnableIn and EnableOut bits are cleared to false.
Example
This example shows a PLLS instruction being used to control three process motors.
Ladder Diagram
PLLS_LadderEx1
PLLS_LadderEx4 PLLS_LadderEx2
PLLS_LadderEx3
PLLS_LadderEx5
PLLS_LadderEx6
Function Block Diagram
The PLLS instruction requires four function block diagram routines to execute properly:
  • PLLS_FBD_1_Motors routine
  • PLLS_FBD_2_PLLS
  • PLLS_FBD_3_ForwardCmds
  • PLLS_FBD_4_ClearCmds
PLLS_FBDex1
PLLS_FBD_1_Motors routine:
PLLS_FBD1MotorsEx_1
PLLS_FBD1MotorsEx_2
PLLS_FBD1MotorsEx_3
PLLS_FBD_2_PLLS routine:
PLLS_FBD2Ex_1
PLLS_FBD_3_ForwardCmds routine:
PLLS_FBD3Ex_1
PLLS_FBD3Ex_2
PLLS_FBD3Ex_3
PLLS_FBD_4_ClearCmds routine:
PLLS_FBD4Ex_1
PLLS_FBD4Ex_2
PLLS_FBD4Ex_3
Structured Text
/* First, execute the individual motors */
/* Execute the Motor 01 logic: get run feedback input, execute PMTR, send output to starter */
MyNG_PLLS_Motor01.Inp_1RunFdbkData := Motor01_RunFdbk;
PMTR (MyNG_PLLS_Motor01, 0, 0, 0, 0, 0);
Motor01_Starter := MyNG_PLLS_Motor01.Out_Run1Data;
/* Execute the Motor 02 logic: get run feedback input, execute PMTR, send output to starter */
MyNG_PLLS_Motor02.Inp_1RunFdbkData := Motor02_RunFdbk;
PMTR (MyNG_PLLS_Motor02, 0, 0, 0, 0, 0);
Motor02_Starter := MyNG_PLLS_Motor02.Out_Run1Data;
/* Execute the Motor 03 logic: get run feedback input, execute PMTR, send output to starter */
MyNG_PLLS_Motor03.Inp_1RunFdbkData := Motor03_RunFdbk;
PMTR (MyNG_PLLS_Motor03, 0, 0, 0, 0, 0);
Motor03_Starter := MyNG_PLLS_Motor03.Out_Run1Data;
/* Copy the Motor 01 Status to the PLLS array [0] */
MyNG_PLLS_Motors[0].Sts_Available := MyNG_PLLS_Motor01.Sts_Available;
MyNG_PLLS_Motors[0].Sts_Stopped := MyNG_PLLS_Motor01.Sts_Stopped;
MyNG_PLLS_Motors[0].Sts_Starting := MyNG_PLLS_Motor01.Sts_Starting1;
MyNG_PLLS_Motors[0].Sts_Running := MyNG_PLLS_Motor01.Sts_Running1;
MyNG_PLLS_Motors[0].Sts_Stopping := MyNG_PLLS_Motor01.Sts_Stopping;
/* Copy the Motor 02 Status to the PLLS array [1] */
MyNG_PLLS_Motors[1].Sts_Available := MyNG_PLLS_Motor02.Sts_Available;
MyNG_PLLS_Motors[1].Sts_Stopped := MyNG_PLLS_Motor02.Sts_Stopped;
MyNG_PLLS_Motors[1].Sts_Starting := MyNG_PLLS_Motor02.Sts_Starting1;
MyNG_PLLS_Motors[1].Sts_Running := MyNG_PLLS_Motor02.Sts_Running1;
MyNG_PLLS_Motors[1].Sts_Stopping := MyNG_PLLS_Motor02.Sts_Stopping;
/* Copy the Motor 03 Status to the PLLS array [2] */
MyNG_PLLS_Motors[2].Sts_Available := MyNG_PLLS_Motor03.Sts_Available;
MyNG_PLLS_Motors[2].Sts_Stopped := MyNG_PLLS_Motor03.Sts_Stopped;
MyNG_PLLS_Motors[2].Sts_Starting := MyNG_PLLS_Motor03.Sts_Starting1;
MyNG_PLLS_Motors[2].Sts_Running := MyNG_PLLS_Motor03.Sts_Running1;
MyNG_PLLS_Motors[2].Sts_Stopping := MyNG_PLLS_Motor03.Sts_Stopping;
/* Now execute the Lead / Lag / Standby instruction */
PLLS (MyNG_PLLS, MyNG_PLLS_Motors, 0);
/* Now take the commands coming out of PLLS and forward them to the PMTR instances */
/* Program commands to Motor 01: */
/* Forward the Program Lock command: */
if (MyNG_PLLS_Motors[0].PCmd_Lock)
then
MyNG_PLLS_Motors[0].PCmd_Lock := 0;
MyNG_PLLS_Motor01.PCmd_Lock := 1;
end_if;
/* Forward the Program Unlock command: */
if (MyNG_PLLS_Motors[0].PCmd_Unlock)
then
MyNG_PLLS_Motors[0].PCmd_Unlock := 0;
MyNG_PLLS_Motor01.PCmd_Unlock := 1;
end_if;
/* Forward the Program Start command: */
if (MyNG_PLLS_Motors[0].PCmd_Start)
then
MyNG_PLLS_Motors[0].PCmd_Start := 0;
MyNG_PLLS_Motor01.PCmd_Start1 := 1;
end_if;
/* Forward the Program Stop command: */
if (MyNG_PLLS_Motors[0].PCmd_Stop)
then
MyNG_PLLS_Motors[0].PCmd_Stop := 0;
MyNG_PLLS_Motor01.PCmd_Stop := 1;
end_if;
/* Program commands to Motor 02: */
/* Forward the Program Lock command: */
if (MyNG_PLLS_Motors[1].PCmd_Lock)
then
MyNG_PLLS_Motors[1].PCmd_Lock := 0;
MyNG_PLLS_Motor02.PCmd_Lock := 1;
end_if;
/* Forward the Program Unlock command: */
if (MyNG_PLLS_Motors[1].PCmd_Unlock)
then
MyNG_PLLS_Motors[1].PCmd_Unlock := 0;
MyNG_PLLS_Motor02.PCmd_Unlock := 1;
end_if;
/* Forward the Program Start command: */
if (MyNG_PLLS_Motors[1].PCmd_Start)
then
MyNG_PLLS_Motors[1].PCmd_Start := 0;
MyNG_PLLS_Motor02.PCmd_Start1 := 1;
end_if;
/* Forward the Program Stop command: */
if (MyNG_PLLS_Motors[1].PCmd_Stop)
then
MyNG_PLLS_Motors[1].PCmd_Stop := 0;
MyNG_PLLS_Motor02.PCmd_Stop := 1;
end_if;
/* Program commands to Motor 03: */
/* Forward the Program Lock command: */
if (MyNG_PLLS_Motors[2].PCmd_Lock)
then
MyNG_PLLS_Motors[2].PCmd_Lock := 0;
MyNG_PLLS_Motor03.PCmd_Lock := 1;
end_if;
/* Forward the Program Unlock command: */
if (MyNG_PLLS_Motors[2].PCmd_Unlock)
then
MyNG_PLLS_Motors[2].PCmd_Unlock := 0;
MyNG_PLLS_Motor03.PCmd_Unlock := 1;
end_if;
/* Forward the Program Start command: */
if (MyNG_PLLS_Motors[2].PCmd_Start)
then
MyNG_PLLS_Motors[2].PCmd_Start := 0;
MyNG_PLLS_Motor03.PCmd_Start1 := 1;
end_if;
/* Forward the Program Stop command: */
if (MyNG_PLLS_Motors[2].PCmd_Stop)
then
MyNG_PLLS_Motors[2].PCmd_Stop := 0;
MyNG_PLLS_Motor03.PCmd_Stop := 1;
end_if;
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