# Menu 34 − AMC Reference Selector

Mode: RFC‑A

Reference selector

Parameter | 34.001 AMC Stop Mode
--- | ---
Short description | Defines the stopping mode used by AMC
Mode | RFC‑A
Minimum | 0 | Maximum | 3
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
0 | Profile
1 | No Profile
2 | Profile Stop
3 | No Profile Stop

AMC Stop Mode (34.001) defines the actions taken when AMC Stop Reference (34.002) is selected. When the motion controller is enabled AMC Stop Reference (34.002) is continuously updated with stop position until the stop reference is selected. AMC Stop Reference (34.002) is then used as the target position for the profile generator.

0 (Profile)

When AMC Stop Mode (34.001) = 0 the stop reference is updated with the position at which the profile would reach zero speed based on the current profile constrains and outputs, i.e. AMC Profile Output Position (38.008), AMC Profile Output Speed (38.009) and AMC Profile Output Acceleration (38.010). When AMC Stop Reference (34.002) is set to 0 (stop) the slave will stop under the constraints applied to the profile generator when the stop was requested.

1 (No profile)

When AMC Stop Mode (34.001) = 1 the stop reference is updated with AMC Slave Position (33.004). When AMC Stop Reference (34.002) is set to 0 (stop) the profile generator is disabled and the slave will stop as quickly as possible.

2 (Profile Stop)

This mode is the same as the profiled stop mode except that AMC Reference Select (34.007) is automatically changed to 0 if the following error exceeds the limit defined by AMC Following Error Window (41.007).

3 (No Profile Stop)

This mode is the same as the no profile stop mode except that AMC Reference Select (34.007) is automatically changed to 0 if the following error exceeds the limit defined by AMC Following Error Window (41.007).

Note that when a software or hardware limit is active AMC Stop Reference (34.002) is updated with the stop position for the stop mode selected in AMC Hardware Limit Stop Mode (41.023) or AMC Software Limit Stop Mode (41.024).

Parameter | 34.002 AMC Stop Reference
--- | ---
Short description | Defines the reference used when the stop reference is selected
Mode | RFC‑A
Minimum | −VM_AMC_POSITION | Maximum | VM_AMC_POSITION
Default |  | Units | UU
Type | 32 Bit Volatile | Update Rate | 4ms write
Display Format | Standard | Decimal Places | 0
Coding | RO, VM, ND, NC, PT

See AMC Stop Mode (34.001).

Parameter | 34.003 AMC Position Reference
--- | ---
Short description | Defines the reference used when AMC Reference Select = 1
Mode | RFC‑A
Minimum | −VM_AMC_POSITION_REF | Maximum | VM_AMC_POSITION_REF
Default | 0 | Units | UU
Type | 32 Bit User Save | Update Rate | AMC sample rate read
Display Format | Standard | Decimal Places | 0
Coding | RW, VM

See AMC Reference Select (34.007).

Parameter | 34.005 AMC Rotary Mode
--- | ---
Short description |
Mode | RFC‑A
Minimum | 0 | Maximum | 6
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

When AMC Roll-over Limit (31.010) is set to a none zero value and AMC Rate Selected (31.013) >= 500μs the change of position added to the input integrator of the profile generator is controlled by AMC Rotary Mode (34.005). Although the position parameters are shown with a range from zero to AMC Roll-over Limit (31.010) - 1 additional "turns" information is used internally to allow the rotary modes to operate correctly. The maximum number of turns that can be accumulated is given by 231-1 / AMC Roll-over Limit (31.010) rounded down to the nearest integer, e.g. if AMC Roll-over Limit (31.010) = 106 then the maximum number of "turns" is limited to 231-1/106 = 2147. For the following modes to operate correctly the difference between the internal value of the profile input integrator, profile output integrator and the slave source integrator in any rotary mode must not exceed this maximum value. If the system does not remain within this limit there will be movement in the opposite direction to that expected.

Note that in relative position mode the change of position is the value in AMC Position Reference (34.003) when a relative move is selected and in absolute position mode it is the difference between AMC Position Reference (34.003) and AMC Profile Input Position (38.006), i.e. Δ = AMC Position Reference (34.003) - AMC Profile Input Position (38.006).

In modes 4, 5 and 6 the variable maximum VM_AMC_POSITION_REF is modified to allow AMC Position Reference (34.003) to be positive or negative with a maximum value greater than AMC Roll-over Limit (31.010) - 1, i.e. a movement of more than one "turn" can be requested. Note that because AMC Position Reference (34.003) can be greater than AMC Roll-over Limit (31.010) the change of position in absolute mode is only calculated when AMC Reference Select (34.007) is changed to 1 from another reference or when AMC Reference Select (34.007) = 1 and a change of AMC Position Reference (34.003) is detected. In absolute position mode the number of "turns" moved by the slave is AMC Position Reference (34.003) / AMC Roll-over Limit (31.010) rounded down to the nearest integer and the final position within the rollover limit is the remainder from this calculation for a positive position reference or the remainder + AMC Roll-over Limit (31.010) for a negative position reference.

0 (Shortest)

The change of position at the input integrator of the profile generator is limited to ±AMC Roll-over Limit (31.010)/2. In this mode the profile output position will move to the input position by the shortest path and can rollover the zero or AMC Roll-over Limit (31.010) -1 boundary as required.

1 (Forward)

If the change of position at the input integrator of the profile generator is negative the change of position added to the integrator is modified so that -Δ becomes AMC Roll-over Limit (31.010) - Δ. This has the effect of making any reverse movements into forward movements by forcing the profile to rollover the AMC Roll-over Limit (31.010) - 1 boundary as shown below.

2 (Reverse)

If the change of position at the input integrator of the profile generator is positive the change of position added to the integrator is modified so that +Δ becomes Δ - AMC Roll-over Limit (31.010). This has the effect of making any forward movements into reverse movements by forcing the profile to rollover the zero boundary as shown below.

3 (No Rollover)

If the change of position at the input integrator of the profile generator would cause the integrator to rollover the zero or AMC Roll-over Limit (31.010) - 1 boundary the change of position is modified so that -Δ (rollover the zero boundary) becomes AMC Roll-over Limit (31.010) - Δ and +Δ (rollover the AMC Roll-over Limit (31.010) boundary) becomes Δ - AMC Roll-over Limit (31.010). This has the effect of preventing the profile input position from crossing the zero or AMC Roll-over Limit (31.010) - 1 boundary.

Note that if AMC Rotary Mode (34.005) is set to 3 when the motion controller is enabled and AMC Profile Output Speed (38.009) > 0 it may not be possible to stop the slave under the constraints of the profile generator before it crosses a boundary.

4 (Multiple Turns Forward)

If the change of position at the input integrator of the profile generator is negative and greater than -AMC Roll-over Limit (31.010) the change of position added to the integrator is modified so that -Δ becomes AMC Roll-over Limit (31.010) - Δ. This has the effect of making any reverse movements into forward movements by forcing the profile to rollover the AMC Roll-over Limit (31.010) - 1 boundary. The change of position is ignored by the profile if it is less than -AMC Roll-over Limit (31.010).

5 (Multiple Turns Reverse)

If the change of position at the input integrator of the profile generator is positive and less than AMC Roll-over Limit (31.010) the change of position added to the integrator is modified so that +Δ becomes Δ - AMC Roll-over Limit (31.010). This has the effect of making any forward movements into reverse movements by forcing the profile to rollover the zero boundary. The change of position is ignored by the profile if it is greater than AMC Roll-over Limit (31.010).

6 (Multiple Turns Delta)

In this mode the change of position is added directly to the input integrator of the profile generator and the direction of movement is defined by the sign of the position change.

Parameter | 34.006 AMC Speed Reference
--- | ---
Short description | Defines the speed reference used when AMC Reference Select = 2
Mode | RFC‑A
Minimum | −VM_AMC_SPEED | Maximum | VM_AMC_SPEED
Default | 0.00 | Units | UU/ms
Type | 32 Bit User Save | Update Rate | AMC sample rate read
Display Format | Standard | Decimal Places | 2
Coding | RW, VM

AMC Speed Reference (34.006) is used as the input to the profile generator when AMC Reference Select (34.007) = 2.

Parameter | 34.007 AMC Reference Select
--- | ---
Short description | Defines the input to the profile generator
Mode | RFC‑A
Minimum | 0 | Maximum | 7
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | AMC sample rate read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
0 | Stop
1 | Position Abs
2 | Speed
3 | Cam
4 | EGB
5 | Home
6 | Position Rel
7 | Position Profile

AMC Reference Select (34.007) selects the input to the profile generator as shown below.

AMC Reference Select (34.007) | Reference | Action on select
0 | AMC Stop Reference (34.002) | AMC Stop Reference (34.002) is no longer updated
1 | AMC Position Reference (34.003) | See position mode below
2 | AMC Speed Reference (34.006) |
3 | Cam system output | Cam system started from AMC Cam Start Index (35.001) and AMC Cam Start Position In Segment (35.002)
4 | Electronic gearbox output | Electronic gearbox is started
5 | Homing system output | Homing sequence is started
6 | AMC Position Reference (34.003) | See position mode below
7 | AMC Profile Input Position (38.006) | See position mode below

Position Mode

Example 1 - Absolute Move

When AMC Reference Select (34.007) is set to 1 the position delta between AMC Position Reference (34.003) and AMC Profile Input Position (38.006) is continuously written to AMC Profile Input Position (38.006) and the slave will move to the reference position.

Index | AMC Position Reference (34.003) | AMC Reference Select (34.007)
1 | 60 | 1
2 | 120 | 1
3 | 300 | 1
4 | 0 | 1

Example 2 - Relative Move

When AMC Reference Select (34.007) is set to 6 and a change of reference position is detected or when AMC Reference Select (34.007) is changed to 6 from another reference then AMC Position Reference (34.003) is added to AMC Profile Input Position (38.006) and the slave will move relative to AMC Profile Input Position (38.006). If the slave is required to move by the same distance in successive moves then AMC Position Reference (34.003) can be changed to zero and then set to the required reference or AMC Reference Select (34.007) can be toggled between mode 6 and 7. When AMC Reference Select (34.007) is set to 7 (profile position) the AMC Profile Input Position (38.006) is held at the previous value and the slave will continue to move to or remain at the profile input position.

Index | AMC Position Reference (34.003) | AMC Reference Select (34.007)
1 | +60 | 6
2 | +60 to 0 to +60 | 6
3 | +120 | 6
4 | -300 | 6

It should be noted that instead of changing AMC Position Reference (34.003) it is possible to toggle AMC Reference Select (34.007) between modes 6 and 7 to initiate another relative move of 60 user units for index 2.

Reference Selector and Trigger

AMC Reference Select (34.007) can be automatically changed in the following modes.

Mode | Reference after change
AMC Stop Mode (34.001) = 2 or 3 | 0
AMC Action On Event (34.008) = Cam On Freeze | 3
AMC Action On Event (34.008) = EGB On Freeze | 4
Homing system (menu 40) | 0

AMC Reference Select Trigger (34.009) can be used to set AMC Reference Select (34.007) on a change of reference. This allows AMC Reference Select (34.007) to be changed automatically and a reference to be continuously written to AMC Reference Select Trigger (34.009). It should be noted that when AMC Reference Select (34.007) and AMC Reference Select Trigger (34.009) are changed in the same sample AMC Reference Select (34.007) = AMC Reference Select Trigger (34.009).

Parameter | 34.008 AMC Action On Event
--- | ---
Short description | Defines the function of the AMC on a positive transition of the master freeze flag
Mode | RFC‑A
Minimum | 0 | Maximum | 2
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
0 | None
1 | Cam On Freeze
2 | EGB On Freeze

0 (None)
This feature is disabled.

1 (Cam On Freeze)
The cam system is started and AMC Reference Select (34.007) is set to 3 when a freeze event is produced by the freeze system (positive transition of the master freeze flag) in the position feedback interface selected by the AMC Master Source Select (32.001) and AMC Master Freeze Select (32.007). The diagram below shows the effect of selecting the Cam by writing directly to AMC Reference Select (34.007) or by using the action on a freeze event.

When AMC Reference Select (34.007) is written directly the first position change used by the Cam is taken between position datum PN and position datum PN+1. Therefore the change of position used by the Cam begins at position datum PN, which is the first datum after AMC Reference Select (34.007) is modified. When the freeze event is used to change AMC Reference Select (34.007) the first position change used by the Cam always starts at the point where the freeze event occurred, and so the change of position seen at the input to the Cam is with reference to the position at the freeze event.

2 (EGB On Freeze)
The EGB system is started and AMC Reference Select (34.007) is set to 4 when a freeze event is produced by the freeze system in the position feedback interface selected by the AMC Master Source Select (32.001) and AMC Master Freeze Select (32.007). The input position is derived in the same way as described for the Cam.

It should be noted that AMC Action On Event (34.008) is disabled when a hardware or software limit is active.

Parameter | 34.009 AMC Reference Select Trigger
--- | ---
Short description | The reference selector is set to the reference trigger when a change is detected
Mode | RFC‑A
Minimum | 0 | Maximum | 7
Default | 0 | Units |
Type | 8 Bit Volatile | Update Rate | AMC sample rate read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
0 | Stop
1 | Position Abs
2 | Speed
3 | Cam
4 | EGB
5 | Home
6 | Position Rel
7 | Position Profile

See AMC Reference Select (34.007).