MCV_RmvPlug

The MCV_RmvPlug FB is used to check whether and which of the 16 axes interfaces are blocked by unacknowledged commands of the PLCopen FBs. After checking, this FB can be used to remove detected blockages.

This FB serves diagnostic purposes and must only be used during the development phase of a project.

Block diagram

Parameters of the FB

VAR_INPUT
	check_plug	BOOL	Starts the check to discover which of up to 16 axis interfaces are blocked by a task not acknowledged by the PLC.
	clear_all_plugs	BOOL	Acknowledges all tasks which are blocking an axis interface.
	clear_ax_01	BOOL	The blocking of each axis interface by an unacknowledged task can be removed separately.

	clear_ax_16	BOOL
VAR_OUTPUT
	any_blocked	BOOL	Is TRUE if after the start of the check of the axis interfaces a blocking due to an unacknowledged task is detected at one or more axis interfaces.
	highest_id_blocked	BOOL	Indicates the index number of the axis with the highest number that is blocked due to an unacknowledged task.
	blocked_ax_01	BOOL	The blocking of each axis interface by an unacknowledged task can be indicated separately. The value is TRUE at each blocked axis interface.

	blocked_ax_16	BOOL

Behavior of the FB

The function block can be command independently of the state of the axis.
The check for blocked axis interfaces is started via the "check_plug" input. An axis interface is block and thus incapable of reporting other commands issued to the assigned axis if a command is applied at the interface as processed for more than 10 successive PLC cycles, but has not been acknowledged by the PLC. The blocking command is identified by its ordinal number and this is stored.
The "any_blocked" output becomes TRUE if at least one axis interface is blocked.
If an axis is blocked, the "blocked_ax_01" ... "blocked_ax_16" assigned to an axis becomes TRUE.
If any axis is blocked, the "highest_id_blocked" output indicates the highest ordinal number of all blocked axes.
Via the "clear_all_plugs" input, for every blocked axis precisely the command is acknowledged by this FB whose ordinal number has been stored for the axis.
For each axis, blockage can be individually removed via the "clear_ax_01" ... "clear_ax_16" inputs.