Glossary

Glossary

Block

This is a named piece of information created by the user as part of an instrument configuration. A block is essentially an alias to a process variable. A block can have logging enabled and will then appear in the final data file.

Blockserver

This is a :term:`Server` element of the IBEX control system that is responsible for managing a :term:`Block` and also a :term:`Configuration`

Client Server

IBEX, like :term:`EPICS`, is a client-server system. In such systems background processes (servers) provide information for clients (such as a GUI or command line). Multiple clients can communicate with a single server process over the network.

Component

A component in IBEX is, essentially, a mini-configuration. It can be used to create a configuration for a sub-set of devices attached to an instrument. When the component is included in a configuration, the configuration "inherits" all the definitions from the component.

Configuration

A configuration defines the blocks, IOCs, macros and other items needed to control the instrument. More specifically, a configuration is an information structure which defines and describes an instrument to IBEX.

DAE (Data Acquisition Electronics)

The DAE is a set of electronic cards housed in a VXI/VME crate located in the instrument cabin/pod and maintained by ISIS electronics group. The DAE contains two types of card:

1. Detector cards (many): these cards record neutron counts
2. Environment/period card (only one): this card distributes timing signals etc. and maintains global counters (e.g. number of ISIS pulses, proton charge delivered (PPP))

EPICS

EPICS is an open-source software framework for creating distruibuted control systems (i.e. for controlling devices which may be distributed across a network). EPICS is the underlying framework used to create IBEX.

ICP (Instrument Control Program)

The ICP (sometimes called the ISIS ICP) is a :term:`Server` element of the IBEX control system that controls communication with the DAE. the ICP is also responsible for writing the RAW experiement data file at the end of a run or experiment.

IOC

An IOC (Input/Output Controller) is an :term:`EPICS` process that provides some service, often managing a device. For example, access to a Eurotherm temperature controller is controlled via an IOC process that provides :term:`Process Variable` for the relevant control elements

PV (Process Variable)

This is a named piece of information in the EPICS system, such as a temperature setpoint or readback. A PV has structured name that uniquely identifies it on the network. An example of such a name, in this case for a motor, is: IN:LARMOR:MOT:MTR0101