Structured Parameter - AxisIntfIn

Structure: AxisIntfIn

Structure of parameters related to the axis interface

wSyncGroup

An identification number of the synchronization group to assign this axis to.

xDrvFwd

Forward direction command for one axis. It is used as long as the axis is not assigned to any synchronization group. If it is assigned to a synchronization group, it gets the commands via direction commands of the group.

xDrvRev

Reverse direction command for one axis. It is used as long as the axis is not assigned to any synchronization group. If it is assigned to a synchronization group, it gets the commands via direction commands of the group.

i_xDrvRdyStat

Inputs of ready status of the axis. The information can be obtained from bit 1 of the status word of the Altivar drive.

Ready status information has to be interlocked (logical AND) with information that the drive is communicating correctly and is in operational state.

The procedure of obtaining this information depends on the fieldbus used. The following examples show the implementation for CANopen and EtherNet/IP.

Example of CANopen status verification for node 3:

VAR
      GET_STATE_Node: CIA405.GET_STATE;
      xNodeOperational: BOOL;
END_VAR
_____________________________________________
(* Check the CANopen node with NodeId 3 *)
GET_STATE_Node(
      NETWORK:= 1,
      ENABLE:= NOT GET_STATE_Node.CONFIRM AND NOT (GET_STATE_Node.ERROR > 0),
      TIMEOUT:= 1000,
      DEVICE:= 3);

IF GET_STATE_Node.CONFIRM OR (GET_STATE_Node.ERROR > 0) THEN
      xNodeOperational:= (GET_STATE_Node.STATE = 5);
END_IF

Example of EtherNet/IP status Verification for a device with connection id 257:

VAR
      xEipHealth: BOOL;
END_VAR
_____________________________________________
(* Check the Ethernet/IP device with connection Id 257  *)
xEipHealth:= UINT_TO_BOOL(EipGetHealth(i_uiconnId:= 257));

If the communication with a drive in the synchronization group is interrupted, the function block must recognize the communication interruption to stop the movement of any other drives in that group or connected to that group.

It can lead to a hazardous situation if one of the motors stops due to unsuccessful communications between the controller and drive, and the other motors of the synchronization group continue movement until the configured maximum position deviation is reached.

The function block must have information about the status of all drives. If one of the drives is not ready, the function block does not authorize to start the movement of the synchronization group. If one of the ready bits turns FALSE during movement, all drives belonging to the synchronization group are stopped.

xEncRdyStat

Provides information to the function block about the status of the encoder. This input must be TRUE to start the movement and must stay TRUE through the duration of the entire movement. When this input is set to FALSE during movement, the function block enters an alarm state and stops the movement.

When the internal encoder interface of Altivar drives is used, set the signal to TRUE when the drive is in an operational state (while controlling the drive via a fieldbus).

When an external encoder is used (for example absolute encoder connected to a fieldbus), this input must be set to TRUE only when the encoder is in an operational state and providing a valid position value.

wDrvSpdRef

Speed reference for the axis in asynchronous mode [RPM]. In synchronous mode, it is the speed reference defined by the synchronization group.

iDrvSpdActl

Actual speed of the axis [RPM].

diEncPos

Actual position of the motor axis in encoder pulses. The function bock supports encoders with resolution up to 32 bits. Overflows of encoder interfaces with lower resolution than 32 bits are automatically handled by the function bock.

wIntfResol

Defines the bit resolution of the encoder interface used. For the internal encoder interface of Altivar drives, 16 bit is used. Resolution of the interface of absolute encoders of the XCC-range is 25 bits.

32-bit interface resolution is supported only for interfaces of integer type (-2147483648...2147483647). 32-bit interfaces of unsigned type (0...4294967296) are not supported.

wDrvAcc

Acceleration time in asynchronous mode.

wDrvDec

Deceleration time in asynchronous mode.

wDrvLsp

Minimum allowed speed of the axis [RPM]. If possible, always set this value to 0. The minimum allowed speed is respected in both synchronous and asynchronous modes. If an axis with a non-zero minimum speed is added to a synchronization group, all axes within the group have to respect this minimum speed. The minimum speed value for each axis is calculated from the speed ratio of the axis.

wDrvHsp

Maximum allowed speed of the axis [RPM]. The parameter must always exceed the configured minimum allowed speed. The maximum allowed speed is respected in both synchronous and asynchronous modes. All axes within the group have to respect the maximum speed. The maximum speed value for each axis is calculated from the speed ratio of the axis. The maximum speed of each synchronization group is limited by the maximum speed of its slowest axis.

rDrvSpdLin

Linear speed of the axis at nominal motor speed [m/s]. The value is used to calculate the actual position deviation between axes with different parameters.

wDrvSpdNom

Nominal motor speed [RPM]. The value is used to calculate the actual position deviation between axes with different parameters.

rEncPulsPerRevo

Number of encoder pulses per revolution of the motor axis. If the encoder is not attached to the motor, the value of pulses per motor revolution must be calculated and written to this input.

If the resolution of used encoder is high compared to the resolution of the encoder interface, (for example, higher than 8192 pulses per revolution for 16-bit encoder interface) it is necessary to scale down the number of pulses per revolution to prevent position loss.

xEncType

Encoder type:

oTRUE = absolute

oFALSE = incremental

After a power cycle, if the configured encoder type does not correspond to the physical encoder type, an invalid position may be determined.

rPosOfst

Target position offset of the axis defines the requested distance of the axis from the mean position of axes within the synchronization group. The value is in meters if the relation between nominal speed of the motor and linear speed of the axis is defined, or in encoder increments if the relation is not defined.

wAxisWght

Statistical weight of the axis. Enter 1 if only simple physical axes are synchronized. If there is a virtual axis connected to the axis interface, enter the number of physical axes contained in this virtual axis.

xInstSync

This parameter enables immediate synchronization. If the parameter is TRUE, the axis can enter and leave synchronization groups even if the axis or the group is not in standstill. It also allows the axis to switch between synchronization groups on-the-fly. You must ensure that the axis enters and leaves axis groups only in controlled conditions.

i_xRst

Alarm reset input. Resets the alarm with a rising edge on the input.