FB_ProcessHandlerBase

This function block is used in injection molding machines to switch from injection pressure to holding pressure.

Syntax:

FUNCTION_BLOCK FB_ProcessHandlerBase IMPLEMENTS I_ProcessHandler
VAR_INPUT
END_VAR
VAR_OUTPUT
END_VAR

Name	Type	Description
Axis	I_AxisBase	An interface to the axis to be monitored.
BadSwitchOver	BOOL	TRUE if an undesired switchover occurred.
ProcessValue	LREAL	The process value to be monitored.
SwitchOver	BOOL	TRUE if an expected switchover occurred.

Name	Description
GetControlParameter	This method can be used to get access to the parameter container of the axis pressure controller.
GetProcessValues	This method is used to update the FB with a range of actual values (pressure, position, state) of the axis. This method is called cyclically by the axis. The application is not intended to call this method directly.
GetSwitchEnable	This method is used to read back the rules for the switchover.
GetSwitchParameter	This method may be used to read back parameters of the switchover rules.
SetControlParameter	This method can be used to assign a parameter container to the axis pressure controller.
SetSwitchEnable	This method is used to define the rules for the switchover. See below for more information.
SetSwitchParameter	This method may be used to define parameters of the switchover rules.

If the monitored axis is in an inactive state (Init, Ready, Idle), the FB is inactive.

An active command of the axis also activates the monitoring.

The rules set with SetSwitchEnable determine the response:

If no faulty switchover has been detected yet:

If bSwitchOnPressure is TRUE and the process value exceeds ePressureThreshold and the axis was moved longer than eGardingTravel from the start point, an expected switchover is detected.
If bSwitchOnTravel is TRUE and the axis has traveled longer than eTravelThreshold from the start point, an expected switchover is detected.
If bSwitchOnTime is TRUE and the time since the start of monitoring exceeds the eTimeThreshold, an expected switchover is detected.
If there is more than one active rule the first match will cause the expected switchover.

If there was still no switchover:

If eTimeout is set to more than 0.0 and the time since the start of monitoring exceeds eTimeout, a faulty switchover is detected.
If the axis position falls below eAlarmPositionLimit, a faulty switchover is detected.
If eAlarmPressureLimit is set to more than 0.0 and the process value exceeds eAlarmPressureLimit, a faulty switchover is detected.

Further Information