Yaskawa DSD 406 - Manual (Page 104)

Glossary
100 Glossary
3/21/96
PAC Diagram – A drawing, resembling a schematic diagram, which shows the
various PAC tasks and the unique interconnection of those PAC tasks.
PAC task – The smallest unit which can be programmed in the PAC language.
Numerous types of PAC tasks are provided, each performing a specific, well
defined function. Each type of PAC task may be used numerous times in a PAC
design. Each PAC task is represented by a block on the PAC Diagram.
PAC task number – A unique number assigned by the PAC programmer to
each PAC task on the PAC Diagram. These numbers may be assigned in any
order and serve only as a means of identifying unique sources of information in
the PAC program. The system will support up to 32,767 PAC tasks with the
allowable task numbers being 1 to 32767.
Parameter upload – The process of a computer sending all settable
parameters (i.e. the .PAR file) to a DSD 406/412 drive. This process can be
used to set up the drive with a set of tuned constants.
Parameter download – The process of the DSD 406/412 drive sending all of
its settable parameter values (i.e. the .PAR file) to a computer. This process
can be used for memory backup. A parameter download is the only data
transfer process that can occur while the drive is running a motor.
Passive Hub – A central component in LAN star networks that splits the
network signal. Data integrity is ensured over a distance of 100 feet for a 4-port
Passive Hub.
PCB – Printed Circuit Board.
PCDU – Portable Control/Display Unit. A device which can plug into a drive or
an RDC, via a cable with a modular connector (similar to a telephone cord), that
has two lines of 16 character alphanumeric display and a 30 key keyboard. It
allows the viewing and setting of variables.
PCU – Power Conversion Unit. The power conversion unit refers to the
hardware and software associated with the power conversion from the AC lines
to the motor. Specifically, it refers to the hardware and software associated with
the PCU microprocessor as well as the power related components. The PCU is
responsible only for the power conversion process, not determination of how
much power should be converted (which is a function of the DCU).
Per-unit value – A per-unit value is a method of representing a quantity where
the value 1.0 represents the “Rated” value for that quantity. Whereas the
“Rated” value is generally a dimensioned value, the Per-Unit value is a
dimensionless quantity.