View source for Project Example: Main Motion (Function Block Diagram)

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The task's purpose is to use motion Function Blocks such as MC_MoveRelative, MC_MoveVelocity and mc_halt. <br/> 
The main program initializes a startup process in the softMC. <br/>
After the startup process is done, the program sets 'Done' variable and a global variable. <br/>
After 'Done' variable is set, programs 'Axis1' and 'Axis2' are called. <br/>
The application uses two drives and their outputs. <br/>
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After installation of device description file (created by the Configurator) to Device Repository, the drive's address will be declared in the Axis Pool:

[[File:Motion A1.PNG|border|600px]]           [[File:Motion A2.PNG|border|600px]]
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In the EtherCAT Slaves section, we can find the I/O mapping for each device.<br/>
In the picture below Input1, Input2, Input3, Input4, Input5, Input11, Output1, Output2, Output3, Output4 and Output5 are declared as new variables (can also be mapped as existing variables):

[[File:Motion CDHD I_O.PNG|border|600px]]
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The main program uses 'softMC_Startup' FB ('mc_st' Instance) to initialize a startup process in the softMC.<br/>
A rising edge detection will set the 'Done' variable (and also a global variable) and then call programs 'Axis1' and 'Axis2':

[[File:Motion main program FBD.PNG|border|450px]]
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==Axis POU - Declaration Section==
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The declaration section in the Axis programs contains the following instances (as shown in the next picture):<br/>
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1. '''MC_POWER_01 -''' an instance of MC_Power FB.<br/>
This Function Block enables/disables an axis.<br/>
If the axis is associated with a real drive, a state machine is invoked to enable/disable the drive via PDO.<br/>
If the axis is simulated, a MC-Basic subroutine is invoked to enable/disable the axis.<br/>
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2. '''MC_MoveVelocity_01 -''' an instance of MC_MoveVelocity FB.<br/>
This Function Block commands a never ending controlled motion at a specified velocity.<br/>
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3. '''MC_halt_01 -''' an instance of MC_halt FB.<br/>
This Function Block commands a controlled motion stop. The axis is moved to the state ‘DiscreteMotion’, until the velocity is zero. With the ‘Done’ output set, the state is transferred to ‘Standstill’.<br/>
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4. '''MC_MoveRelative_01 -''' an instance of MC_MoveRelative FB.<br/>
This Function Block commands a controlled motion of a specified distance relative to the set position at the time of the execution.<br/>
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5. '''mc_reset_01 -''' an instance of MC_Reset FB.<br/>
This Function Block makes the transition from the state ‘ErrorStop’ to ‘Standstill’ or ‘Disabled’ by resetting all internal axis-related errors. It does not affect the output of the FB instances.<br/>
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[[File:Motion Axis1 declaration.PNG|border|1000px]] 


==Axis POU - Implementation Section==
Note: Programs 'Axis1' and 'Axis2' are similar.<br/>
Output5 is turned on when POU is called.<br/>
Input1, Input2, Input3 and Input4 are attached to Output1, Output2, Output3 and Output4 respectively.<br/>
If Output1 is triggered, the MC_Power FB is enabled. <br/>
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[[File:Motion Axis1 implementation FBD.PNG|border|400px]]
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If Axis is enabled, Input4 is not on, MC_MoveRelative_01.Busy has a False value and a rising edge is detected in Input2, then MC_MoveVelocity FB is executed with a positive direction.<br/>

If Axis is enabled, Input4 is not on, MC_MoveRelative_01.Busy has a False value and a rising edge is detected in Input3, then MC_MoveVelocity FB is executed with a negative direction.<br/>
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[[File:Motion Axis1 implementation1 FBD.PNG|border|600px]]
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When a falling edge is detected in Input2 or Input3, then a boolean variable 'stop_jog" is  triggered. <br/>
If axis is enabled and 'stop_jog' is TRUE, the MC_halt FB is executed.<br/>
If Input2 and Input3 are not on, Input 4 is on, then MC_MoveRelative is executed.<br/>
If Input11 is on, then MC_Reset is executed.<br/> 
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[[File:Motion Axis1 implementation2 FBD.PNG|border|550px]]
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==Visualization==

The program is controlled by a graphic interface:
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[[File:Motion visualization.PNG|border|700px]]
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When the startup process of softMC is done, the blue lamp is turned on.<br/>
The user can turn on and off Inputs 1 - 4 for each drive and watch their status in the green lamps.