Equipments (Devices) > SCA06 > Ladder > Motion Control > Motion Control Command > MC

Block responsible for enabling/disabling the drive axis.

Ladder Representation

MC_Power_block

Execution Features

Program Memory Size	40 Bytes
Data Memory Size	4 Bytes

Block Structure

Variable Type	Name	Data Type	Description
VAR_IN_OUT	Axis	BYTE	Selection of operation axis (0 - Real axis)
VAR_INPUT	Enable	BOOL	Block enabling
VAR_OUTPUT	Status	BOOL	Output enabling
	Valid	BOOL	Flag indicating validity of the output signals
	Error	BOOL	Error in the execution flag
	ErrorID	WORD	Identifier of the occurred error
VAR	MC_POWER_INST_0	MC_POWER	Instance of access to block structure

Operation

This block performs an Enable/Disable command of the Axis axis according to the Enable input, disabling it Enable is FALSE and enabling if Enable is TRUE.

NOTE!

When the MC_Power block is used to enable/disable the real axis, no digital inputs must be programmed for the Enable function (option 1), or an Alarm A0120 may occur.

When enabling the real axis for the first time, the drive may operate in grid position, depending on the value of parameter P0773. The position proportional gain (P0159) must be set to obtain a better drive performance.

When the real axis is disabled, the axis status will be Disabled. When enabling the real axis, the axis status will change to Standstill.

When EN has FALSE value, Status remains FALSE. The Status output is activated when the block finishes the execution successfully, remaining at TRUE level until Enable receives FALSE.

If there is any error in the execution, the Error output is enabled and ErrorID displays an error code according to the table below.

Code	Description
66	Drive in the "ErrorStop" status.
71	P202 different from 4.

Example in Ladder

MC_Power_example01

MC_Power_example02

MC_Power_example03

On the leading edge of POWER_COMMAND, the real axis is enabled and its status, the system marker REAL_AXIS_STATUS (%SW6004), is changed to Standstill (%SW6004 = 2). The Status output is set.

After the transition from 0 to 1 of MOTION_COMMAND, the MC_MotionAbsolut block is executed and the positioning for the position 10 revolutions starts. The axis status is changed to "Discrete Motion" (%SW3406 = 6).

While positioning is executed, POWER_COMMAND is reset. Since the BufferMode of the MC_Power is set to Buffered, the axis will be disabled only in the positioning completion.

When the positioning is finished, the Done output of the MC_MotionAbsolut block is set for 1 scan cycle and the axis is disabled (MC_Power.Enable = 0). The axis status changes to "Disable" (%SW6004 = 0).

Example in ST

The example below displays the instructions for applying the example above in the ST language.

VAR

POWER_COMMAND, POWER_STATUS, MOVE_COMMAND, MOVE_FINISH : BOOL;

MC_POWER_INST_0 : FB_MC_Power;

MC_MOVEABSOLUTE_INST_0 : FB_MC_MoveAbsolute;

END_VAR

MC_POWER_INST_0.Enable := POWER_COMMAND;

MC_POWER_INST_0(Axis:=0);

POWER_STATUS := MC_POWER_INST_0.Status;

MC_MOVEABSOLUTE_INST_0.Execute := MOVE_COMMAND;

MC_MOVEABSOLUTE_INST_0(

Axis:=0,

Continuousupdate:=0,

Position:=LREAL#10.0,

Velocity:=200.0,

Acceleration:=1000.0,

Deceleration:=1000.0,

Jerk:=0.0,

BufferMode:=0);

MOVE_FINISH := MC_MOVEABSOLUTE_INST_0.Done;