Yaskawa DSD 406 - Manual (Page 102)

Glossary
98 Glossary 3/21/96
is either categorized as a fault or not). The special CDU function allows
overriding of that initial definition.
Fixed point number – A number system used internally in the computer which
is encoded in a specific manner. Fixed point numbers have a limited range of
values which they can represent. In the case of the fixed point numbering
system used for the PAC language, the maximum value which can be
represented is +/- 32,767.99998 and the smallest non-zero value is +/- 0.000015.
The advantage of fixed point numbers is that some of the arithmetic operations
such as addition, subtraction, and comparison execute much faster than a value
represented in floating point.
Floating point number – A number system used internally in the computer
which is encoded in a specific manner. In this case the encoding method (i.e.
format) is a widely used format developed by the IEEE organization. The
encoding scheme is similar to scientific notation of numbers which make use of
number field and exponent. For example, 1.2 x E-2 is a scientific notation of the
number 0.012 (1.2 times ten to the minus 2 power). The advantage of floating
point numbers is that they can represent a very large range of values from the
very small to the very large.
HIT – High Impedance Transceiver. A type of transceiver circuitry on a LAN
Node that electrically connects to the coaxial cable. HIT Nodes may be
interconnected in star or bus networks. MicroTrac DSD uses this type of
transceiver.
Kernel – This is the fixed (i.e. non-changeable) code for the DCU
microprocessor which forms the operating system of the microprocessor. As
such, it controls the generation of the various scans, the order of execution of the
PAC tasks, the information passed to and from the PAC tasks and the execution
of other standard code not directly associated with the PAC tasks such as the
control of the CDU or LAN handler.
LAN – Local Area Network. A high speed serial communication network
which allows two-way communications between multiple devices (referred to as
Nodes) all connected to the same communications cable. The specific LAN
used is “ARCNET”.
LAND – LAN Driver transceiver. A type of transceiver circuitry on a LAN
Node that electrically connects to the coaxial cable. LAND Nodes may be
interconnected in a star network only.
LAN Node – A point in a network where service is provided, service is used, or
communications channels are interconnected.