E898 BooNE Params (E25)

The physical devices within the ACNET system are accessed via unique 8-character "Device Names" which hide the gory details of the actual physical interface. Each device name consists of a one character class followed by a colon and a six character name unique to that class.  The classes are the same as for the ACNET index pages: "B:" for booster, "L:" for linac, etc.  All devices specific to MiniBooNE begin with "E:".  For example, "E:HT860" would be the current in the horizontal trim magnet.

In general, each device has a "Set value", a "Readback value", and a "Digital Status".  Often these come from physically different sources.  In the E:HT860 example above, the "Set value" goes to a DAC in the power supply reference, while the readback comes from a monitor of the actual current going to the magnet.   Not all devices have all properties.  For example, there is no "Set value" on the E:HP864, the horizontal beam position after the jack pipe.

The simplest way to look at devices is the "Parameter Page", which is a generic primary application for organizing  devices.  The devices specific to MiniBooNE can all be found on E25, which looks like this:

For each device, you can see the set value (yellow) and the readback value (green).  The database keeps track of converting the raw data into the appropriate units (shown in white).  If you have privilege (which you do not on the 10th floor), you can change a value by putting the cursor over the set field, and typing in a new value and clicking, or by turning a control knob.  If a setting changes, the original value appears to the left in purple, and you can restore it by clicking on it. The original (purple) value will be lost if you exit the page, go to a different subpage, or iconize the window, so be sure you are happy with the state of things before leaving the page!

Typing a device name on the left of a blank line of any parameter page, or overtyping a device name which is already there, will cause that device to read out. However, unless you save the page, the page will go back to its original configuration after you exit.

Device names are also how things are referenced in the plotting operations described throughout this document.

Another useful feature is the "Help" option. To use this, place the cursor over any device name, and hit the F7 (Help) key. This will launch a Netscape window which will give you information about that device.