ARFA

A utomated R apid F illing A utomatus

General

The ARFA is part of the experiment structure of ARCA.(Automated Rapid Chemistry Automatus)
It is a machine that automizes the filling of repositories with ion-exchanger substances.
These repositories are used in research about properties of super heavy elements.
Each repository has 20 tubes that can be filled.

New Version ARFA_FIT is a modification to fit the current electronics of ARFA. Last measurements detected that the output current is around 8V. The FPGA just needs 5V.

Construction

The main functunality is realized through five pneumatic valves from Festo Company. These are two pairs with the same function (2a,3a left; 2b,3b right) for the two different kinds of repositories(1). And one for the filling pressure in the syringe(4). These two kinds of repositories(1) are called: "right-side" or "left-side", analog to the milling side. The single difference of these repositories(1) is the side of the milling. The milling is constructed for the forward movement of the repository(1). If the lever(3) is moved forward the repository will also move forward. If the lever(3) is moved backwards the lever leaves the milling and slides to the next milling. Hereinafter it is not distinguished between these because the operation is the same for each side.
This picture shows the contruction of the ARFA with currently selected "right-side" repository.

1. repository (with 20 tubes)
2.a locking left (passive)
2.b locking right (active)
3.a lever/feed left (passive)
3.b lever/feed right (active)
4. syringe
The maschines' functionality should cover the follwing:

1. Default position:
   • repository(1) locked
   • right side selected
2. Release the locking(2) to unlock the repository(1) and allow a forward movement in the next step.
3. Move the lever(3) forward and the repository(1) one position further so the next tube can be filled
4. Lock the repository(1)
   • So it is fixed for the filling process,
   • and the lever(3) that moved the repository forward can move back into the next milling and is ready for the next forward movement without moving the repository back.
5. Move the lever(3) backwards to prepare the next forward movement (compare 2.b)
6. Fill the tubes of the repository with the substance inside the syringe(4)for the filltime set by the user.

A pump can aspirate the filling substance that does not enter the tubes.

The syringe that contains the ion-exchanger substance is fitted with a mixer that prevents inhomogenities or grafting.

Operation

There are two diffrent ways to control the maschine.

1. Automized Filling where the FPGA runs the execution order with configurable settings as filltime or number of tubes to be filled.
2. Manual Filling where the user can run the execution interactivly. That means also to control the maschines movement as feed or locking.

These two methods can be performed either locally at the hardware case or remotely via a graphical user interface from PC.

Local Control

For local control the switches at the hardware case are used to:

• Set the parameters for automized filling process as:
  • Füllzeit Filltime
    • Filltime (for each tube) (max 100s)
  • *1/*10
    • multiplier for Filltime
  • Röhrchenzahl
    • Number of tubes to be filled (max 20)
  • Magazin (links/rechts)
    • Choose repsository side (left/right)
  • Audio aus
    • Down: An audio signal informs the user that the set number of tubes have been filled
    • Up : No audio signal sounds
  • aus (Pumpe)
    • auto: the pump switches off automaticly after the set number of tubes have been filled
    • man: the pump remains on after the set number of tubes have been filled
• Start the process with the set parameters
• Stop the process
• Control the machine manually : (each action for both kinds of repositories)
  • vor move the repository forward
  • zurück move the lever backwards for next movement
  • Arret ein lock the repository so it is fixed if the lever moves backward
  • Arret aus unlock the repository so it moves forward if the lever moves forward
  • auf not in use
  • ab fill the current tube
  • Pumpe
    • ein : start the pump
    • aus : stop the pump
  • Mischer
    • ein : activate the mixer in the syringe
    • aus : deactivate the mixer in the syringe
  • U/Min :choose mixing speed (in Rpm)

The picture shows the look of the switches at the hardware case.

The remote permission switch is not yet realized at the machine, but is a suggestion to make remote control safe.

• Remote permit (regulate remote access)
  • grant
    • allow remote control
  • deny
    • do not allow remote control but control the maschine locally

Local Manual Filling

Switches at point 3-7 directly activate a pneumatic unit and have a resulting movement.
Change the switches to "Up-Postion" to accomplish a movement and change it back to "Down-Postion" afterwards.
The standard execution order is:

1. Choose the repository-side (Magazin (links/rechts))
2. Pumpe->ein starts the pump
3. Arret aus makes sure the repository is unlocked before it is moved forward
4. vor moves the repository forward through the lever
5. Arret ein makes sure the repository is locked before the lever is moved backwards
6. zurück moves the lever backwards
7. ab keep up for as long as the current tube should be filled
8. more tubes to be filled? goto 3.
9. Pumpe->aus stops the pump

The machine will not allow certain actions that would harm the maschine, e.g. it is not possible to move the lever forward when the repository is locked.

Local Automized Filling

make sure

• The Start - and Stop - switches are set to false (down position).
• All switches for manual control are set to false (down position) (vor/zurück/ein/aus/auf/ab)

before giving the maschine power to prevent unforseen actions.

Manual for Local Automized Filling

1. Prepare mixer
2. Insert repository and syringe with ion-exchanger substances
3. Choose the repository-side (Magazin (links/rechts))
4. Set the number of tubes to be filled (Röhrchenzahl)
5. Set the filltime in seconds (Füllzeit). Maximum setting is 100s but filltime can be increased with multiplier.
6. Set the multiplier (*1/*10). Multiplies the filltime to archieve filltimes longer than 100s
7. Set the audio signal notification (Audio aus)
8. Set the pump options (aus (Pumpe)) to auto or man
9. Start the pump (Pumpe -> ein)
10. Set the mixer rotating frequency (U/Min)
11. Press reset to make new settings valid
12. Set the (Start/Stop) switch to start to begin the process
13. When finished the maschine will stop automatically.
14. If the audio notification sounds press (Audio aus) to stop it.

To interrupt the process set the (Start/Stop) switch to Stop.
If the switch is set to start again the process will continue from where it was interrupted.
If this is not wanted but to start the process from beginning, press (Reset) first!

Remote Control

Remote control allows to control the maschine from a distant place via a LabVIEW programm.

The graphical user interface (GUI) allows remote manual filling, remote automized filling and animation of the current machines' movement. Even if the maschine is not under remote control but local control the current movement of the machine will be displayed.
To remotely control the machine you need a permission that can be given through a switch at the hardware case at the ARFA. If this switch is set to TRUE you will be able to log in. Logging in prevents interference with the local control.
The remote permission switch is not yet realized at the machine, but is a suggestion to make remote control safe.

Remote Manual Filling

To manually control the machines' movement press the corresponding buttons.
Make sure you choose the buttons for the side compatible to your repository.

The execution order is listed in yellow letters. The number for each step corresponds to the number that points to the buttons. There are two different ways for the filling step.

• Start(Manual) will result in a filling as long as pressed (Filltime will be displayed in the box below)
• Start(Filltime) will result in a filling for the period of time set as Filltime at the settings.

Filltime can be set in different units: minutes, seconds or milliseconds. Filltime can also be a combination of those.

Example for Filling process

Magazin type : left
tubes to be filled :n
filltime: 2s

1. Insert repository and syringe with ion-exchanger substances
2. Press PumpON->OK
3. Press Feed left -> forth
4. Press Locking left -> lock
5. Keep pressed Start(Manual) for 2s or change Settings->Filltime to 2s and press Start(Filltime)
6. Press Feed left -> back
7. Press Locking left -> unlock
8. Repeat step 3-7 n-Times
9. Press PumpOFF->OK

The program automatically prohibits actions that would harm the maschine, as moving the repository forward while it is locked. The user is informed either by a messagebox or the button that would lead to a harmful action is grayed out.

Remote Automized Filling

For automized filling make the following settings:

1. Set the repository side to left or right
2. Set the number of tubes to be filled
3. Set the filltime for each tube. (2s = 2000 ms = 1s + 1000ms = ...)
4. Set Audio Signal options
   • True: An audio signal informs the user that the set number of tubes have been filled
   • False: No audio signal sounds
5. Set PumpAutoOff options
   • True: the pump switches off automaticly after the set number of tubes have been filled
   • False: the pump remains on after the set number of tubes have been filled
6. Press Reset
7. Press Start

Config Options

The configuration buttons makes more setting possible.
After pressing the button the window enlarges and the settings in the green boxes appear. Some are indicators to inform the user about the programms performance and give hints to problems. Others are settings to change certain functionalities of the program. The explicit meaning is explained below:

• Intervall (ms)
  • Setting for the ArfaFPGAVI. The state maschine that handles the Automized Filling
• Interupt
  • True: FPGA VI will generate an Interrupt every time the Output changed
• Wait Until Cleared
  • True: The FPGA VI will wait until the Output Loop has aknowledged the Inerrupt.
• wait on IRQ
  • True: The FPGA Monitor Loop will wait for the Interrupt generated by the FPGA VI, before it reads the FPGA Outputs. After receiving the Interrupt, the Output Loop aknowledges the Interrupt.
  • False: The FPGA Monitor Loop reads the FPGA outputs every 50ms.
• GUI Loop Count
  • Shows how often the GUI Loop was executed. This counter should increment if there is a change at the GUI. A change could be button press or a value change.
• Output Loop Count
  • Shows how often the FPGA Monitor Loop was executed.
  • If wait on IRQ is true the counter sould increment every time the FPGA's Output changes.
  • If wait on IRQ is false the counter should increment every 50ms according to the sampling rate set in the loops' "Interrupt Case Structure".
• Anmation Loop Count
  • Shows how often the Animation Loop was executed. This counter should only increment for each maschines' movement.
• Animation Loop Timer
  • Shows how long the Animation Loop takes to display the movement.
• IRQ Count
  • Shows how many interrupts the ArfaFPGAVI has sent. (Interrupt should only be generated if the maschines' output changed)
• FPGA Loop Counter
  • Shows how often the ArfaFPGAVI Loop was executed.
• Local input
  • Shows the currrent position for the controls at the hardware case of the maschine. This can be important for remote control, because the local controls at the hardware case must be in a certain position to allow remote control.
• Remote input
  • Shows the GUI inputs in the look of the local inputs.
• Outputs
  • Shows the current FPGA Outputs
    • Magazin
      • shows the selected repository side
    • nofTubesLeft
      • shows how many tubes are left to be filled
    • Filltime_out
      • shows the set filltime
    • V1-V10
      • shows which valve in active
    • Pump
      • shows the pumps activity
    • running
      • is true when the maschine is active either in Automized Filling or Manual Filling
    • Audio Signal
      • is true as long as the audio signal sounds
    • TOC
      • Timeout Counter for the state maschine
    • Break
      • is true if the current Automized Filling process was interrupted. As long as true the Automized Filling process can be continued whith the "Start" switch. If this is not wanted but to start the process from beginning, press (Reset) first!
    • reset
      • is true if reset is pressed
    • error
      • indicates an error as:
        • giving permit for remote control but the maschine is not in the default position.
        • someone is logged in but is withdrawn permission
        • an unsafe movement is tried to perform as: moving the repository forward while it is locked
    • remote ok
      • indicates that remote control is possible
      • becomes true when permit is given and somebody is loged in
      • stays true is someone is logged in even if the permit is withdrawn
      • becomes false as soon as nobody is loged in
    • locked l
      • indicates that the repository is locked on the left side
    • locked r
      • indicates that the repository is locked on the right side
    • front l
      • indicates that the repository is in front position and left side is choosen
    • front r
      • indicates that the repository is in front position and right side is choosen
    • manual mode
      • indicates that the maschine in currently under manual control.It prevents that the Timeout Counter automticly switches from state to state but only the user decides how long each state takes and when to switch.

Security

To prevent interference between local and remote control the software is fitted with a security check. For that reason remote control is only possible if several requirement are respected.

1. The "remote permission" switch at the hardware case must be set to "True"
   • will be ignored if maschine is not in default position
     • default means False to: Start, Stop, Reset, Pump On, Pump Off, ab, auf, aus, ein, zurueck, vor, break, running, error
2. The "Login" button at the GUI must be set to "True" (green color)
   • will be ignored if
     • maschine is not in default position
     • remote permission is not set to true
3. The maschine can now be operated remotly

To control the maschine localy again

1. The "Login" button at the GUI must be set to "False" (red color)
   • will be ignored if maschine is not in default position

Installing Cables

The I/O signal from the hardware case of ARFA are connected to a SCB-68. (68-Pin Shielded Connector Block)
This connector block is connected to the FPGA. (NI-7831R) The FPGA has 3 connectors each for one connector block. A connector block either act as MIO or DIO type depending on the type of I/Os you want to connect. FPGA's connector0 deals with a connector block as MIO-type, connector1 and connector2 deal with a connector block as DIO-type. The whole project has 36 digital I/Os (DIO) and 2 analog I/Os (AIO). To connect all I/Os to the FPGA, two connector blocks are needed.
One conector block acting as DIO-type to accomondate 26 DIO.
Another conector block acting as MIO-type to accomondate 2 AIO and 10 DIO. Connection should be like this:

Links

FPGA with LabVIEW-Statechart
LabVIEW FPGA and CompactRIO Getting Started Tutorial
Using Single-Cycle Timed Loops to Optimize FPGA VIs

-- TillKoch - 06 Oct 2009