National Instruments GPIB-PC - Manual (Page 32)

Section Two Installation and Configuration
©National Instruments Corp. 2-7 GPIB-PC User Manual
Characteristics of the Instruments
Each instrument used with the GPIB-PC has the following
characteristics:
• A symbolic name of each device on the GPIB (such as DEV5 or
PS5010 ).
• A GPIB-PC access board for each device (e.g., GPIB0 ). The
access board is discussed in Device Map Concepts and Terms
later in this section.
• A primary and, if used, secondary address for each device.
• A time limit that is to be imposed when executing certain
functions. This is to ensure that accessing a powered-off device
does not hang up the GPIB indefinitely.
• A way to terminate I/O transmissions to and from the device.
Some devices require or append an end-of-string character, such
as the ASCII line feed character, to data strings. Others use the
GPIB END message, which is sent or received via the EOI
signal line. Still others use both. Some terminate messages
only when a predetermined number of bytes are sent or
received.
Characteristics of each GPIB-PC
Each GPIB-PC has the following characteristics:
• A symbolic name (such as GPIB0 and GPIB1 ).
• A computer I/O or port address.
• The capability to be designated as the System Controller of the
devices on its bus.
• A time limit that is imposed when executing certain functions.
• A way to terminate I/O transmissions to and from the board
when executing board calls, i.e., by an end-of-string character,
an END message, and/or a byte count.
• An interrupt level that the board uses.