Input Pin Description

Input Pin Description

i_xEn

When TRUE, enables the function block. When FALSE, the FB enters a fallback state. In fallback state, the function block uses the configuration parameters, target speeds, ramps and direction commands to provide output for both drives. Torque limitation of hold drive is set to 300% (is disabled). Internal position calculation of both axes stays active.

Transition between disabled and enabled state of the FB and vice versa while the crane is running is not restricted but is not recommended.

Disabling the FB can be used as a switch to maintenance mode for changing of cables.

i_xDrvFwdHold

Command for forward (upwards) movement of the hold axis. When there is no command for movement of close axis present at the same time, the forward command for the hold axis is used to move both, hold and close axes synchronously.

i_xDrvRevHold

Command for reverse (downwards) movement of the hold axis. When there is no command for movement of close axis present at the same time, the reverse command for the hold axis is used to move both, hold and close axes synchronously.

i_xDrvRdyStatHold, i_xDrvRdyStatClose

Inputs of ready status of both hold and close drives. The information can be obtained from bit 1 of status word of Altivar drives. This information has to be interlocked (logical AND) with an information that the drive is communicating with the controller.

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 any of the two drives is interrupted, the FB has to get the information in order to stop the movement.

Failing to interlock the fieldbus communication status with the ready status of the drive may result in a situation when one of the motors stops because of a communication interruption between the controller and drive. When the FB does not receive information about the loss of communication, the other motor stays in motion.

The FB needs to have information about status of both drives. If one of the drives is not ready, the FB does not authorize start of the movement. If one of the ready bits turns FALSE during movement, both motors are stopped.

i_wDrvSpdRefHold, i_wDrvSpdRefClose

Speed reference for hold and close drives. [rpm]

i_iDrvSpdActlHold, i_iDrvSpdActlClose

Actual speed of hold and close motors read from the drives. [rpm]

i_iDrvTrqActlHold, i_iDrvTrqActlClose

Actual torque of hold and close motors read from the drives.

Use the “Motor torque scope” object (SOTR). Logic address 3226, CANopen index 2002:1B.

The value must be either scaled in the user application to the range -3000...3000 corresponding to -300...300% of nominal motor torque or internally in the GrabControl FB.

To scale the value in your application, divide it by 4.096 and convert it to integer.

To let it scale automatically within the GrabControl FB, connect the un-scaled values and set the i_stPGC.xTrqScopeScale parameter to TRUE.

The values are automatically filtered by a low-pass filter inside the function block. The filtered values are available at the outputs q_iTrqFltrHold and q_iTrqFltrClose.

i_wEncPosHold, i_wEncPosClose

Encoder positions of hold and close axes. The FB is designed to work with position information read out of Altivar drives running in closed loop. Use the Encoder position object (PUC) Logic address 5611, CANopen index 201A:0C.

Encoder value must increase when motor is moving in positive direction.

i_xGrabCalbOpen

Rising edge on this input calibrates position difference corresponding to open state of the grab. You must perform calibration for the soft limit switch function to work. You can perform a new calibration without re-setting the previously calibrated value. If desired position cannot be reached because of previous calibration, you can reset the calibration values by rising edge on input i_xGrabCalbRst.

i_xGrabCalbClosed

Rising edge on this input calibrates position difference corresponding to closed state of the grab. Perform calibration for the soft limit switch function to work. You can perform a new calibration without re-setting the previously calibrated value. If desired position cannot be reached because of previous calibration, you can reset the calibration values by rising edge on input i_xGrabCalbRst.

i_xGrabCalbRst

Rising edge on this input resets calibration values for open and closed grab positions.

i_xClsOnStackEn

TRUE on this input enables automatic closing on stack. Activate this function by applying commands to close and raise the grab simultaneously. When the input is FALSE, automatic closing on stack is disabled and the commands to close and raise are acting on their respective axes.

The input must be TRUE to start the automatic closing on stack. It does not need to stay TRUE for the whole duration of closing.

You can set this input continuously to TRUE. Automatic closing on the stack is only to be used while the grab is on the material.

A load cell detecting that the grab is on the ground may be used to enable automatic closing on stack.

The hold motor is working in a torque limited mode during automatic closing on stack. If activation of the automatic closing on stack function must be suppressed while the grab is mid-air, the user application must take into account the enabling and disabling of the automatic closing on stack function. The situation often results in a detected over speed fault reported by the Altivar drive.

i_xTrqShareEn

TRUE on this input enables sharing of the load between hold and close axes when the grab is closed. When it is FALSE, the axes are position synchronized.

Use torque sharing and switch to position synchronization only when the torque values are too low or unstable for load sharing.

You can configure a torque offset in order to have more torque on the close motor to keep the filled grab closed. See parameter i_stPGC.wTrqAddOnClose.

NOTE: Switching between load sharing and position synchronization while the axes are moving is possible when the position with balanced load is similar to the target position of position synchronization.

Example: In hook mode,when the hook is empty and the torque of one or both axes is too low for effective load sharing, set i_xTrqShareEn to FALSE. And set it to TRUE once the torque increases.

In grab mode, you should set i_xTrqShareEn to TRUE.

i_xScrapEn

TRUE on this input enables the scraping function. Scraping is active only during automatic closing on stack. Ideally it is directly controlled by a modifier button on the joystick. It can share the button with the function of rapid opening. When the button gets released during scraping, the FB automatically changes to standard closing on stack.

i_xHookModeEn

TRUE on this input enables the hook mode. Commands to close drive are ignored in the hook mode. The axes operate either in load sharing or position synchronization mode, based on the state of i_xTrqShareEn input.

NOTE: Switching between hook mode and standard grab operation while the axes are running is possible but not recommended.

i_xRapidOpenEn

The function is active when commands to raise and open and the i_xRapidOpenEn are active at the same time. It enables a fast opening of the grab by moving hold and close axes in opposite directions.

i_xRst

Resets alarms on rising edge, if the cause of the alarm is no longer present.