§3. Basic points

Interaction of user software with a driver is shown on the following drawing:

Рисунок 2. Взаимодействие прикладного пользовательского приложения с драйвером

User software using access library interface conducts a driver enquiry. The driver kernel using equipment inquiry functions provides data access. Equipment inquiry functions may be instrumented with a help of DWizard.

Рисунок 3. Схема взаимодействия пользовательского приложения с оборудованием

Data accessible to user application is represented on 'Data channels' of different types. There are 5 types of channels at all: analog input/output channel, discreet input/output channel and complementing input channel.

Рисунок 4. Каналы данных

Each data channel is characterized with a number of parameters: access type (input/output), channel type (analog, discreet), signal scale and others:

Рисунок 5. Канал данных