Operating procedure

All the operations are handled by computers. Some of them can also be performed independently by mechanical switches (referred to as manually). In the following, the main window of the slow control program running on the MacA and/or MacB display will be referred to simply as the "main window".

Connection of MacB to MacA

The MacA and MacB communicate through the Timbuktu package, which implements the TCP/IP protocols over an Ethernet dedicated line. To make the connection, following procedure outlined below:

• Switch on the MacB computer (energize the VME crate).
• Run Timbuktu on the MacB; you can select it in the Apple (top-left) menu.
• Open the connection selecting the CONTROL button after you entered the TCP/IP number (129.57.188.20).
• Give the username H2OCEBAF and the password WATER.

The window that appears contains a `carbon copy' of the MacA screen: the user in counting room can control all the operations of MacA by using the MacB mouse and keyboard as if the MacB user were using the MacA; BE CAREFUL: the performance is reduced due to the connection: Be patient! wait for the screen to refresh after any action.

Startup of the system

The system startup depends on the history of the shutdown:

After a normal shutdown

In the hall,

• Go to the right side of the right rack and push the green start button of the right box; you will hear a beeping sound;
• Go to the front of the left rack and push the green button near the $emergency$ one;
• Wait for the MacA to be operative;
• Click on the $H2O CEBAF97$ icon (the slow control program for the water target at CEBAF), which is almost in the center of the MacA desktop. The LabView application will run automatically and the slow control main window will be shown;
• Push the arrow button on the top-left side of this window in order to start the program.

The first time the program is run, after MacA power on, it initializes the electronic modules. Every time the program is run, it asks for a new initialization of the electronic modules. Answer YES; a small window with 4 buttons appears. Press all the buttons in order from top to bottom. When the initialization is done the main window comes back.

After an emergency shutdown

• Recognize the cause of the emergency, and fix it.
• Release the emergency button in the hall or in the counting house, depending on which one was used for the emergency shutdown, in order to restore its operation. The system will be energized and a beeping sound will be heard.
• Push the green button near the emergency red button. The beeping sound will be turned off.

System shutdown

The normal procedure:

• Go to the experimental hall;
• Close the program on the MacA; shutdown the MacA;
• Move to the right side of the $Right$ rack and push the red stop button of the right box (the left box is not used).

The emergency procedure:

This procedure is really an EMERGENCY procedure; do not use it for normal operation. Push the $emergengy$ red button in front of the left rack if you are in the hall, or the one in the counting room on the top of the computer monitor. In order to restart the system follow the startup procedure described above.

Waterfall activating

• Check that the slow control program is running on MacA and optional on MacB;
• Check if the pump is on, and in case it isn't turn it on from the switch in front of the right rack or from the switch in front of "Pump Command Module" in the counting room
• Increase the pump speed to desired value in the main window of MacA or MacB (right side);
• Wait about 20 minutes to stabilize the water flow.

Empty target procedure

From the counting house: use the slide on the right of the main window of MacB to set the pump speed to minimum, then switch off the pump by turning off the switch on the front panel of the "pump Command Module" which is located over the MacB monitor;

or

In the hall: one can set the pump speed to minimum either from MacA by using the slide on the right of the main window, or use the button on the front panel of the right rack, and then turn the pump switch on the right rack to ``off'' position.

The reactivating of the pump needs to be done from the same switch used to deactivate it; see "Waterfall Activating Procedure".

Target movement procedure

After the slow control program H2OCEBAF97 is activated,

• Press the motor button on the bottom of the main window of the computer; a motor control window will appear;
• Select the type of movement (up/down, rotation);
• Select the target or the angle; the Move button should be activated if everything is O.K.;
• Press the Move button; a warning message reminds you to be sure of your action. Be sure that the beam is off!!
• During the movement watch the two displays showing the current position and the one to be reached.
• When the final point is reached, a message will inform you of the success of the operation. Otherwise a warning message will tell you about the faulty status.

(Eventual) gas flow operating procedures

The gas filling of the target cell, when empty, has to be done in Hall A: on the right rack there is a self-explaining panel. The washing button has to be pushed (for about 15 minutes) to open the inlet and outlet valves in order to allow the gas to replace the air which fills the target cell.

In order to refill the cell, in the case of very small leakages (remember that the pressure must be about 1.02 Atm), push the pressure bottom of the main window. The pressure control window will appear. The operation is self-explaining. Just remember that the gas flows only if you keep the button pressed.

Calibration of the movement system

For `normal' operation the user does not need any additional information about the movement system. The following calibration tables (target and angle positions versus encoder values) are useful for checking purposes; notice that if the target changes, the calibration has to be performed again. The following values are OK for the waterfall, carbon, beryllium, iron target which was installed in July '96.

Target	Encoder Position
Water	17301
Up Survey	38528
Carbon	42949
Beryllium	47371
Iron	51792
Low Survey	56213

The vertical scale factor is: 1 encoder unit = 5.74 $\mu m$.

The angular correspondence is:

Angle	Encoder Position
0 degree	27361
30.533 degree	26479

that means: 1 encoder unit = 0.035 degree.

When a new calibration is required^A1 only the expert(s) is(are) allowed to perform the following steps:

• Go to the hall;
• Run the calibration program ("setlimits.vi") on MacA in order to allow the computer to get the limits of the movement ranges (up/down and rotation if enabled); this procedure takes several minutes;
• Rotate the target to two angles and take note of the encoder values;
• Write these value on a scrapbook;
• Select sequentially the 6 targets (waterfall and the solid ones) and take note of the encoders values;
• Note ALL the previous and new values in the logbook,
• Move.