Rotary Table Application (RTA)

Mnemonic (Keyboard Shortcut) = RTA

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Purpose

The Rotary Table Application (RTA) instruction is used to control a station-based rotary application. Many of these applications exist in the automation control industry and the goal here is to make it easy for a user to setup and use. The user is required to enter the number of stations, the raw number of pulses per revolution of the table, and the speed and ramp of the indexing moves.

Instruction Parameter Description:

Parameter	Parameter Type	Requirements	Description
Enable	Ladder Input	Must Have	Level-driven. When Enable is ON, the instruction will operate every scan. When Enable is OFF, the instruction is not solved and its Outputs are not updated.
Axis Name	Selectable Dropdown	Must Have	The selected axis this instruction will control. Each AMC module will have from 1 up to 4 depending on the model number.
Abs Move Direction	Selectable Dropdown	Must Have	Select Shortest Path, Always Move Forward or Always MoveReverse. By default, the shortest path will be used to determine the move direction. The other selections will always go their respective directions regardless of distance.
Number of Stations	Constant	Must Have	Set to the number of evenly spaced stations in each revolution.(minimum of 2 stations required)
Pulses per table revolution	Numerical Tag	Must Have	Set to the raw number of pulses per table revolution. This value is NOT scaled.
Index Speed	Numerical Tag	Must Have	Sets the speed of the trapezoidal index moves. This value can be changed while the instruction active. If changed, the new will be used on the next index move after the change is received.
Ramp Rate	Numerical Tag	Must Have	Sets the symmetrical accel and decel of the trapezoidal index move. This value can be changed while the instruction is active. If changed, the new dwell time will be used on the next index move after the change is received.
Absolute Station	Numerical Tag	Optional	Enter the value of the Target Station ID when the Abs Input is triggered
At Station Dwell Time	Numerical Tag	Optional	(Option Enabled if Output Pulse Time selected) When the move is completed the specified dwell time will begin. Once complete the assigned Output will enable. If changed, the new value will be used on the next index move after the change is received.
Use Jerk	Numerical Tag	Optional	When selected, a Jerk value is required. The indexing move will now have s-curve ramps. If used, this value can be changedwhile the instruction is active. If changed, the new value will be used on the next index move after the change is received.
Enable Output	Checkbox	Optional	Enables the Output Control feature.
Output Pulse Time	Numerical Tag	Optional	Select either Turn On, Turn Off, Pulse On, or Pulse Off. If either pulse option is selected, the pulse time parameter must be defined. When selected, the user will have to choose one. When selected, the pulse width, in msecs, will be required and can be changed when the instruction is active. Also, Delay Time is optional and is used to delay the GP output signal from the end of the index move. The signal of the output can be changed while the instruction is active. When left blank, the signal is triggered at the end of the index move. Both the Delay time and the pulse width time can be updated every scan and will be used on the move that starts immediately after the new value is received.
In Progress	Boolean	Optional	A Status tag that indicates whether or not the instruction is active. The AMC module runs asynchronously with respect to the ladder scan so this status should be used for interlocking logic if necessary. This tag is immediately set to 1 when this instruction is enabled unless the axis is currently executing another instruction. When the instruction is complete , this tag is set to 0.
Complete	Boolean	Optional	A Status tag that indicates the execution of this instruction was completed successfully. The AMC module runs asynchronously with respect to the ladder scan so this status should be used for interlocking logic if necessary. This tag is immediately set to 1 when this instruction is complete. When this instruction is enabled successfully, this tag is set to 0.
Current Station	Numerical Tag	Optional	Holds the value of the current/last station where motion stopped.
Instruction Status	Numerical Tag	Optional	A Status tag that contains the Feedback of the Action being performed by this instruction. The high-speed modules run asynchronously with respect to the ladder scan so this status should be used for interlocking logic if necessary. See the Instruction Status Table for bit definitions.

Note : This instruction assumes that all the stations are equally spaced.

Note: Before using this instruction, the axis should be successfully homed and moved into the location of station one. Every subsequent move will be based off that location until the instruction is disabled.

Note: The instruction may not function correctly if the axis is being used in another instruction in ladder. If two separate instructions in ladder use the same axis, the latest one [in the scan cycle(s)] controls the axis.

Instruction Editor

Note : The "On-the-fly" symbol indicates that this value can be changed while the instruction is running.

Parameter Configuration

Parameter Configuration Table

Parameter

Notes

Axis Name

Select the Axis this instruction will control.

Module Name

The Name of the Module name that contains the currently selected Axis/Channel. Displayed for informational purposes only.

InProgress Bit

Enter the tag that will contain the instruction's In Progress status.

Complete Bit

Enter the tag that will contain the instruction's Complete status.

Current Station

Status Tag that contains the value of the current station if motion is stopped or, last station if move is in progress.

Instruction Status

Status Tag that contains the Feedback of the Action being performed by this instruction.

Abs Move Direction

Select Shortest Path, Always Move Forward or Always Move Reverse.

Number of Station

Set to the number of evenly spaced stations in each revolution.

Pulses per Table Rev

Set to the raw number o f pulses per table revolution. This value is NOT scaled.

Index Speed

Set to the speed of the trapezoidal index moves. This value can bechanged while the instruction is active but will not be used until the next index move after the change is received.

Ramp Rate

Set the symmetrical accel and decel of the trapezoidal index move. This value can bechanged while the instruction is active but will not be used until the next index move after the change is received.

Absolute Station

Enter the value of the target station ID when the Abs input is triggered.
This value can bechanged while the instruction is active.but will not be used until the next index move after the change is received.

At Station Dwell Time

Used to delay activation of the GP output signal from the end of the index move. When left blank or has a zero value, the signal is triggered at the end of the index move once the dwell time has expired. Note: The value can bechanged while the instruction is active but will not be used until the next index move after the change is received.

Use Jerk

When selected, a jerk value is required such that will add s-curve ramps to the indexing move. Note: this value can bechanged while the instruction is active but the new value will not be used until the next index move after the change is received.

Enable Output

When selected, the user will have to choose one of the behavior options for the output point: Turn On, Turn Off, Pulse On, or Pulse Off. If a 'Pulse' behavior is selected, the pulse width, in msecs, will be required and can bechanged while the instruction is active but will not be used until the next index move after the change is received.

RTA Structure Definition

Instruction/ Feature Abbreviation	Instruction/ Feature Name	Structure Element
		Field	Name	Default Type
RTA	Rotary Table	In Progress	In Progress	Boolean
		Complete	Complete	Boolean
		Status	Instruction Status	Integer, 32-bit
		PulsesPerRev	Pulses Per Revolution	Float, 32-bit
		IndexSpeed	Index Speed	Integer, 32-bit
		RampRate	Ramp Rate	Integer, 32-bit
		JerkRate	Jerk Rate	Integer, 32-bit
		AbsStation	Absolute Station	Integer, 32-bit
		OutputPulseTime	Output Pulse Time	Integer, 32-bit
		StationDwellTime	Station Dwell Time	Integer, 32-bit
		CurrentStation	Current Station	Integer, 32-bit

This instruction (shown below) has four sub rungs for control:

Enable: Will start the instruction and lock in the current location as station 1.
Fwd: Rising Edge driven and will index to the next to the next station in the positive direction. If the current station is the last one, the move will target station 1.
Rev: Rising edge driven and will index to the next station in the negative direction. If the current station is station 1, then the last station will be targeted.
Move Abs: Rising Edge-driven and will move to the station indicated in the Absolute Station parameter field. If this value is not valid, this move will be ignored.

Move and Instruction Status Definition

Status Bit	Status	Description
1	Px-HSO: Accelerating	This bit shows the current state of the channel while movement is accelerating (when In Progress Bit = ON). After the instruction is Complete, this bit will be OFF.
	PS-AMCx: General Use Status 1	AREG: Waiting For Master Event
		FCO: Waiting for Event Start
		GEAR: Primary Drivetrain Slave is Enabled
		MREG: Correction Move In Progress
		MSEQ: Dwell Period of Timeout is Active
		RTA: Table stopped at station
2	Steady Velocity	This bit shows the current state of the channel or axis while movement is running in steady state (when In Progress Bit = ON). After the instruction is Complete, this bit will be OFF.
3	Px-HSO: Decelerating	This bit shows the current state of the channel while movement is decelerating (when In Progress Bit = ON). After the instruction is Complete, this bit will be OFF.
	PS-AMCx: General Use Status 2	AREG: Waiting For Product Event
		FCO: Tool Slewing to Synchronization
		GEAR: Secondary Drivetrain Slave is Enabled
		RTA: Alert: Invalid Absolute Station Id
4	Px-HSO: Future	Future
	PS-AMCx: General Use Status 3	AREG: Correction Applied
		FCO: Tool is in Synchronization with the Master
		GEAR: Third Drivetrain Slave is Enabled
		MREG, SMOV, VMOV: Position Capture Occurred (1 or 2 scan pulse)
5	Px-HSO: Future	Future
5	PS-AMCx: General Use Status 4	GEAR: Fourth Drivetrain Slave is Enabled
6	Px-HSO: Future	Future
6	PS-AMCx: Application Move	Info – Application Move is in Progress (Movement or active slave )
7	Stopped at Move Target	This bit is ON when the instruction completes and the Target position was achieved without any Errors or Aborts.
8	Stopped at Registration Target	This bit is ON when the instruction completes a Registration function using the Decel to a Stop option without any Errors or Aborts.
9	Aborted - Instruction Disabled	This bit indicates that the instruction was disabled in the ladder by the user
10	Aborted - Hit Limit (See Channel or Axis Status Register)	This bit indicates that either a Limit Switch or Position Limit has been tripped. The Channel or Axis Status will indicate which of the 4 possible conditions has occurred.
11	Aborted - Communications Failure During Move	This bit indicates that communication to the module failed previously. The module may now be ready but the current instruction must be restarted. This condition may occur due to a hot-swap or a loss of communication to a Remote Slave Base.
12	Aborted - IO Fault (See Module Error Register)	If the ESCP (Electronic Short Circuit Protection) becomes active for the Output Channels associated with the current instruction, the instruction will abort since the intended operation will fail. This bit will turn ON and the specific Channel error can be found in the Module Error Code, Bits 2 & 3. Note: Faults on Channels 3-6 will not cause this abort and must be detected using the Channel Status and Module Error Code.
13	Aborted - Over User's Max Accel	In the HSO H/W Configuration Channel setup or the PS-AMC Axis Configuration, the user has the option to either Limit a move to a maximum value or Stop the move once that maximum value is exceeded. If the Channel or Axis is configured to Stop the Move and the instruction exceeds the Maximum value, the instruction will Abort and one of these related bits will turn ON.
14	Aborted - Over User's Max Decel
15	Aborted - Over User's Max Velocity
16	Px-HSO: Aborted - Position Limit out of range	If the tag values assigned to the Position Limits are out of range, the instruction will Abort and this bit will be ON. Note: Affected by Channel Scaling.
16	PS-AMCx: Future	Future
17	Px-HSO: Aborted - Target out of range	When Position Limits are configured and the Instruction Target position is known to be beyond the Position Limits, the Instruction will Abort before any motion starts and this bit will be set ON. Note: Affected by Channel Scaling.
17	PS-AMCx: Abort Invalid Input/Edge Combination	This will occur when an axis is configured for RPI ( Reset Position by Input ) and that axis is running an instruction ( or it’s slave ) and tries to use the same input as RPI with a different edge.
18	Aborted - Velocity out of range	The HSO outputs can be run at a maximum of 1MHz. If the instruction commands a velocity greater than 1MHz, the instruction will Abort with this bit ON. Note: Affected by Channel Scaling.
19	Aborted - Accel/Decel/Ramp out of range	If the value assigned to the Acceleration or Deceleration Ramp is outside the valid range (1 to 100e6), the instruction will Abort and this bit will be ON. >Note: Affected by Channel Scaling.
20	Aborted - Jerk/S-Curve out of range	If the Jerk value is outside the valid range of 1 to 100e9or the S-Curve value is outside the range of 1 to 100e6, the instruction will Abort and this bit will be ON. Note: Affected by Channel Scaling.
21	Px-HSO: Future	Future
21	PS-AMCx: Axis Status	Additional information will be stored in the Axis Status register tag
22	Px-HSO: Future	Future
22	PS-AMCx: Aborted - General Parameter	There is a general parameter out of range ( does not include velocity, ramps, jerk, registration, or presets )
23	Px-HSO: Future	Future
23	PS-AMCx: Aborted – Preset Parameter	There is a preset parameter out of range
24	Aborted - Registration parameter out of range	At least one of the Registration input parameters is out of range. Parameters such as: Delay Registration Action by, Decel to a Stop or Output Pulse Time.
25	Alert - Target reached during Accel/Decel	If a home switch is reached while accelerating or decelerating, this bit will be set. To ensure repeatable accuracy, you must adjust your parameters or move further away from home and re-home so that the switch is reached at a steady speed.
26	Alert - Parameter Adjusted: Over User's Max Accel	In the HSO H/W Configuration Channel setup, the user has the option to either Limit a move to a maximum value or Stop the move once that maximum value is exceeded. If the Channel is set to Use the Maximum Value and the instruction exceeds this value, the instruction will not Abort and the output will be limited to the Maximum Value with the related Alert bit set to ON.
27	Alert - Parameter Adjusted: Over User's Max Decel
28	Alert - Parameter Adjusted: Over User's Max Velocity
29	Px-HSO: Alert - Position Rolled Over	These bits are set to report the occurrence of a Roll Over and/or Roll Under. They will remain set for 3 scans and then clear. This makes it possible to detect multiple roll over and/or roll under events using ladder code. The default rollover positions are +/- 2,147,483,647 but Channel Scaling affects this range and if Rotary Mode is enabled, the range will always roll under at zero, and roll over to zero.
30	Px-HSO: Alert - Position Rolled Under
31	Future	Future
32	Future	Future