Motion Axis Jog (MAJ)

CompactLogix
 5380,
CompactLogix
 5480,
ControlLogix
 5580,
Compact GuardLogix
 5380, and
GuardLogix
 5580 controllers
Use the Motion Axis Jog (MAJ) instruction to move an axis at a constant speed until you tell it to stop.
Architecture and safety support
Architecture
Standard
Safety
CompactLogix 5370, ControlLogix 5570, Compact GuardLogix 5370, and GuardLogix 5570 controllers
Yes
No
Compact GuardLogix 5380, CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, and GuardLogix 5580 controllers
Yes
No
Available Languages
Ladder Diagram
MAJ_LD_avail_v31
Function Block
This instruction is not available in function block.
Structured Text
MAJ(Axis,MotionControl, Direction,Speed, SpeedUnits, AccelRate, AccelUnits, DecelRate, DecelUnits, Profile,
AccelJerk, DecelJerk, JerkUnits, Merge, MergeSpeed LockPosition, LockDirection);
Operands
Operand
Type
Tip:
 AXIS_CONSUMED is supported by
Compact GuardLogix
 5580,
CompactLogix
 5380, and
CompactLogix
 5480 controllers only.
Type
Tip:
 AXIS_GENERIC is supported by the
ControlLogix
 5570 and the
GuardLogix
 5570 controllers only.
Format
Description
Axis
AXIS_CIP_DRIVE
AXIS_VIRTUAL
AXIS_CIP_DRIVE
AXIS_VIRTUAL
AXIS_GENERIC_DRIVE
AXIS_SERVO
AXIS_SERVO_DRIVE
Tag
Name of the axis to jog. For controllers that support the REF_TO motion data types, the supported axis operand type can be replaced by an equivalent REF_TO type.
Motion Control
MOTION_INSTRUCTION
MOTION_INSTRUCTION
Tag
Control tag for the instruction.
Direction
DINT
DINT
Immediate
For This Jog Direction
Enter
Forward
0
Reverse
1
Speed
REAL
REAL
Immediate or Tag
Speed to move the axis in Speed Units.
Speed Units
DINT
DINT
Immediate
Which units do you want to use for the Speed?
  • Units per sec (0)
  • % of Maximum (1)
  • Units per MasterUnits (4)
Accel Rate
REAL
REAL
Immediate or Tag
Acceleration rate of the axis in Accel Units.
Accel Units
DINT
DINT
Immediate
Which units do you want to use for the Accel Rate?
  • Units per sec
    2
    (0)
  • % of Maximum (1)
  • Units per MasterUnit
    2
    (4)
Decel Rate
REAL
REAL
Immediate or Tag
Deceleration rate to the axis in Deceleration Units.
Decel Units
DINT
DINT
Immediate
Which units do you want to use for the Decel Rate?
  • Units per sec
    2
     (0)
  • % of Maximum (1)
  • Units per MasterUnit
    2
    (4)
Profile
DINT
DINT
Immediate
Select the velocity profile to run the jog:
  • Trapezoidal (0)
  • S-curve (1)
Accel Jerk
REAL
REAL
Immediate or Tag
You
must
 always enter values for the Accel and Decel Jerk operands. This instruction only uses the values if the Profile is configured as S-curve.
  • Accel Jerk is the acceleration jerk rate for the axis
  • Decel Jerk is the deceleration jerk rate for the axis.
Use these values to get started.
  • Accel Jerk = 100 (% of Time)
  • Decel Jerk = 100 (% of Time)
  • Jerk units = 2
Enter the jerk rates in these Jerk Units.
0 = Units per sec
3
1 = % of Maximum
2 = % of Time (use this value to get started)
4 = Units per MasterUnit
3
6 = % of Time-Master Driven
Decel Jerk
REAL
REAL
Immediate or Tag
Jerk Units
DINT
DINT
Immediate
Merge
DINT
DINT
Immediate
Do you want to turn all current axis motion into a pure jog governed by this instruction regardless of the motion instructions currently in process?
  • NO — Choose Disabled (0)
  • YES — Choose Enabled (1)
Merge Speed
DINT
DINT
Immediate
If Merge is Enabled, which speed do you want to jog at?
  • Speed of this instruction — Choose Programmed = 0
  • Current speed of the axis — Choose Current = 1
Lock Position
REAL
REAL
Immediate or Tag
Position on the Master Axis where a Slave should start following the master after the move has been initiated on the Slave Axis.
See the Structure section below for more information.
Lock Direction
UINT32
UINT32
Immediate or Tag
Specifies the conditions when the Lock Position should be used.
See the Structure section below for more information.
Structured Text
This Operand
Has These Options Which You
Enter as Text
Or Enter as a Number
Axis
No enumeration
Tag
MotionControl
No enumeration
Tag
Direction
No enumeration
Immediate
Speed
No enumeration
Immediate or Tag
SpeedUnits
units per sec
% of maximum
unitspermasterunit
0
1
4
AccelRate
AccelUnits
units per sec
2
% of maximum
unitspermasterunit
2
0
1
4
DecelRate
DecelUnits
units per sec
2
% of maximum
unitspermasterunit
2
0
1
4
Profile
Trapezoidal
S-curve
0
1
AccelJerk
No enumeration
Immediate or Tag
You
must
 always enter a value for the Accel and Decel Jerk operands. This instruction only uses the values if the Profile is configured as
S-curve.
Use these values to get started.
  • Accel Jerk = 100 (% of Time)
  • Decel Jerk = 100 (% of Time)
DecelJerk
No enumeration
Jerk Units
units per sec
3
%ofmaximum
%oftime
seconds
unitspermasterunit
3
 %oftimemasterdriven
masterunits
0
1
2 (use this value to get started)
3
4
5
6
Merge
disabled
enabled
0
1
Merge Speed
programmed
current
0
1
Lock Position
No enumeration
Immediate or Tag
Lock Direction
none
immediateforwardonly
immediatereverseonly
positionforward
positionreverse
0
1
2
3
4
See Structured Text Syntax for more information on the syntax of expressions within structured text.
MOTION_INSTRUCTION Structure
To See If
Check To See If This Bit Is Set To
Data Type
Notes
A false-to-true transition caused the instruction to execute.
EN
BOOL
The EN bit stays set until the process is complete and the rung goes false.
The jog was successfully initiated.
DN
BOOL
An error happened.
ER
BOOL
The axis is jogging.
IP
BOOL
Any of these actions stop this jog and clear the IP bit:
  • Another MAJ instruction supersedes this MAJ instruction.
  • Motion Axis Stop (MAS)instruction.
  • Merge from another instruction.
  • Shutdown command.
  • Fault Action.
Description
Use the MAJ instruction to move an axis at a constant speed without regard to position.
Programming Guidelines
IMPORTANT:
If you change move parameters dynamically by any method, that is by changing move dynamics [Motion Change Dynamics (MCD) instruction or Motion Coordinated Change Dynamics (MCCD)] or by starting a new instruction before the last one has completed, be aware of the risk of velocity or end position overshoot.
A Trapezoidal velocity profile can overshoot if maximum deceleration is decreased while the move is decelerating or is close to the deceleration point.
An S-curve velocity profile can overshoot if:
  • Maximum deceleration is decreased while the move is decelerating or close to the deceleration point; or
  • Maximum acceleration jerk is decreased and the axis is accelerating. Keep in mind, however, that jerk can be changed indirectly if it is specified in % of time.
For more information, see Troubleshooting Axis Motion.
Guidelines
Details
In ladder diagram, toggle the rung condition each time you want to execute the instruction.
This is a transitional instruction:
In ladder diagram, toggle the rung-condition-in from cleared to set each time you want to execute the instruction.
In structured text, condition the instruction so that it only executes on a transition.
In structured text, instructions execute each time they are scanned.
Condition the instruction so that it only executes on a transition. Use either of these methods:
  • qualifier of an SFC action
  • structured text construct
For more information, see Structured Text Syntax.
Use the jerk operands for S-curve profiles.
Use the jerk operands when the instruction uses an S-curve profile.
You must fill in the jerk operands regardless of the profile.
Use % of Time for the easiest programming and tuning of jerk.
For an easy way to program and tune jerk, enter it as a % of the acceleration or deceleration time.
For more information, see Tune an S-curve Profile.
Use Merge to cancel the motion of other instructions.
How you want to handle any motion that’s already in process?
If You Want To
And You Want To
Then Set
Add the jog to any motion already in process
arrow_right (2)
Merge = Disabled
Merge Speed = Programmed
The instruction ignores Merge Speed but you must fill it in anyway.
End the motion from other instructions and just jog
Jog at the speed that you set in this instruction
Merge = Enabled
Merge Speed = Programmed
Jog at the speed that the axis is already moving
Merge = Enabled
Merge Speed = Current
The instruction ignores the value that you put in the Speed operand.
Be careful if you start another jog while the axis is already jogging.
If you start a new MAJ instruction while one is already in process, you can cause:
  • an accelerating axis to overshoot its speed
  • a decelerating axis to reverse
    (revision 15 and earlier)
This happens if the MAJ instructions use an S-curve profile. The new MAJ instruction cancels the old MAJ instruction. The axis uses the speed, acceleration, deceleration, and jerk of the new instruction.
For more information, see Troubleshoot Axis Motion.
Use an MAS instruction to stop the jog.
Use an MCD instruction to change the speed while jogging.
When MAJ (Merge = Enabled) is used on any axis associated with a coordinate system and a coordinated motion instruction is running on it, Coordinate system’s maximum deceleration is used to stop remaining axes. If the coordinate system contains orientation axes, Coordinate system’s Orientation maximum deceleration is used for stopping remaining Rx, Ry or Rz axes.
Structure
See Input and Output Parameters Structure for Single Axis Motion Instructions for the input and output parameters that are available for the MAJ instruction via the Master Driven Speed Control (MDSC) function. Before any of these parameters is active, you must execute an MDAC instruction and it must be active (IP bit is set).
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. A major fault can occur if an uninitialized reference or a reference of incorrect type is passed to the Axis Operand. See Common Attributes for operand-related faults.
Execution
Ladder Diagram
Condition/State
Action Taken
Prescan
The .EN, .DN, .ER, and .IP bits are cleared to false.
Rung-condition-in is false
The .EN bit is cleared to false if either the .DN or .ER bit is true.
Rung-condition-in is true
The .EN bit is set to true and the instruction executes.
Postscan
N/A
Structured Text
Condition/State
Action Taken
Prescan
See Prescan in the Ladder Diagram table
Normal execution
See Rung-condition-in is false, followed by Rung-condition-in is true in the Ladder Diagram table.
Postscan
See Postscan in the Ladder Diagram table.
Error Codes
See Motion Error Codes (.ERR) for Motion Instructions.
Runtime Error Condition
The slave move must start at rest if Speed Units = Seconds or Master Units. This condition may occur when the MAJ with Speed = Seconds or Master Units is started while another MAJ is in progress (merging or replacement mode).
Extended Error Codes
Use Extended Error Codes (EXERR) for more instruction about an error.
If ERR is
And EXERR is
Then
Cause
Corrective Action
13
Varies
An operand is outside its range.
The EXERR is the number of the operand that is out of range. The first operand is 0.
For example, if EXERR = 3, then check the Speed.
EXERR
MAS Operand
0
Axis
1
Motion Control
2
Direction
3
Speed
5
Accel Rate
7
Decel Rate
15
-1
The coordinated system has a Maximum Deceleration of 0.
Go to the Properties for the coordinate system axis and set a Maximum Deceleration.
0 or more
An axis in the coordinate system has a Maximum Deceleration of 0.
  1. Open the Properties for the axis.
  2. Use the EXERR value to see which axis has the Maximum Deceleration of 0.
  3. The axis that you are jogging has a deceleration rate of 0.
Changes to Status Bits
Motion Instruction Predefined Data Type Status Bits
See Status Bits for Motion Instructions (MAM, MATC, MAJ) When MDAC Is Active.
MAJ Changes to Instruction Status Bits
Bit Name
Meaning
MotionStatus
The motion status bit for your axis.
Bit Number
Meaning
AccelStatus
0
The axis is not accelerating (FALSE state).
DecelStatus
1
The axis is not decelerating (FALSE state).
MoveStatus
2
The axis is not moving (FALSE state).
JogStatus
3
The axis is not jogging (FALSE state).
GearingStatus
4
The axis is not gearing (FALSE state).
HomingStatus
5
The axis is not homing (FALSE state).
StoppingStatus
6
The axis is stopping (TRUE state).
AxisHomedStatus
7
The axis is not homed (FALSE state).
PositionCamStatus
8
The axis is not position camming (FALSE state).
TimeCamStatus
9
The axis is not time camming (FALSE state).
PositionCamPendingStatus
10
The axis does not have a Position Cam Pending (FALSE state).
TimeCamPendingStatus
11
The axis does not have a Time Cam Pending (FALSE state).
GearingLockStatus
12
The axis is not in a Gear Locked condition (FALSE state).
PositionCamLockStatus
13
The axis is not in a Position Cam Locked condition (FALSE state).
TimeCamLockStatus
14
The axis is not in a Time Cam Locked condition (FALSE state).
MasterOffsetMoveStatus
15
The axis is offset (TRUE state).
CoordinatedMotionStatus
16
Sets when the MDAC instruction executes (TRUE state). Clears when the instruction completes (FALSE state).
TransformStateStatus
17
The axis is part of an active transform (TRUE state).
ControlledByTransformStatus
18
The axis is moving because of a transform (TRUE state).
DirectVelocityControlStatus
19
The axis is not under Direct Velocity Control (FALSE state).
DirectTorqueControlStatus
20
The axis is not under Direct Torque Control (FALSE state).
JogLockStatus
24
MAJ is Locked to Master in MDSC Mode (TRUE state).
The bit is cleared when a MGS, MGSD, MAS, or MASD is executed.
If either the Slave or Master axis (or both) is paused by changing its speed to 0, then the JogLockStatus bit stays set.
Master Driven Mode
The bit is set when the Lock Direction request is satisfied.
The bit is not used when the enumeration is NONE.
For the enumerations Immediate Forward Only and Immediate Reverse Only, the JogLockStatus bit is set immediately when the MAJ is initiated.
For the enumeration Position Forward Only and Position Reverse Only, the bit is set when the Master Axis crosses the Master Lock Position in the specified direction.
The JogLockStatus bit is cleared when the Master Axis reverses direction and the Slave Axis stops following the Master Axis. The JogLockStatus bit is set again when the Slave Axis resumes following the Master Axis.
Time Driven Mode
The bit is not used when the enumeration is NONE.
MasterOffsetMoveLockStatus
26
Master offset Move is Locked to master in MDSC Mode (TRUE state).
MaximumSpeedExceeded
27
Sets when the maximum axis speed that is specified in the axis configuration is exceeded during a move (TRUE state). Clears when the velocity is reduced below the limit (FALSE state).
MAJ Changes to Single Axis Status Bits
If Merge Is
Then the Instruction Changes These Bits
Bit Name
State
Meaning
Disabled
JogStatus
TRUE
Axis is Jogging.
Enabled
JogStatus
TRUE
Axis is Jogging.
MoveStatus
FALSE
Axis is no longer Moving.
GearingStatus
FALSE
Axis is no longer Gearing.
Master Driven Speed Control (MDSC) and Motion Direct Command Support
The Motion Direct commands are not available in the instruction tree for the MDAC or MDCC instruction. You must program an MDAC in one of the supported programming languages before you execute an MAJ in Time Driven Mode. A runtime error will occur if an MDAC is not previously executed in an MAM or MAJ in Master Driven Mode.
The Motion Direct Command supports the MDSC enumerations speed, acceleration, deceleration, and Jerk for MAJ.
Note that Event Distance and Calculated Data are not supported parameters for the MAJ and Motion Direct Command.
Master Driven Speed Control (MDSC) and CIP Axis Manual Tune and Motion Generator
Event Distance and Calculated Data parameters are not supported for MAJ.
Examples
Ladder Diagram
MAJ_LD_ex_v31
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