Yaskawa VCD 723 - Manual (Page 115)

Glossary
109 Glossary
9/15/93
RDC – Remote Display Controller LAN Node PCB. A board that includes the
LAN Node circuitry and the software to control what is displayed on each of up
to 31 RDUs. This device also communicates with the drives over the LAN.
RDU – Remote Display Unit. A device that has a 16 character alphanumeric
display and a 5-1/2 digit plus sign numeric display. This device is controlled by
an RDC.
RDU message – The data that is displayed on both displays of the RDU. The
source of the message is defined in the RDC by a Menu Item number, Drive
number, Channel number, Subchannel number, decimal position, a flag stating
what type of message it is (whether the message is modifiable or not), and - if it
is modifiable - the minimum and maximum allowable limits of an entered value.
RI/O – Remote I/O [Input/Output] Controller LAN Node PCB. A board that
includes the LAN Node circuitry and the software to control outputs to and
monitor inputs from Remote (Logic or Analog) I/O boards. This device also
communicates with the drives over the LAN.
Scan – This term refers to the frequency at which a particular PAC task will
execute. All PAC tasks programmed in a particular scan will execute in the same
time frame. MicroTrac DSD is provided with four timed scans and one
background scan. Each PAC task programmed in a timed scan will execute once
in that time frame. The background scan executes each PAC task once in
whatever time is left over from the timed scans and then starts over executing
each task again.
SCDU – Standard Control/Display Unit. The 4-1/2 digit numeric display, 4
push buttons (keypad) and multi-color LED on the drive. It allows viewing and
setting of variables.
Selected menu item – The menu item number in the RDU’s menu that is being
displayed.
Severe fault – An abnormal condition whose severity requires immediate action
by the microprocessor sensing the error. An example of a severe error is an IST
condition sensed by the PCU. In this case, the PCU disconnects the load; it does
not wait for the PAC program to command load disconnect. (Also see FAULT
definition.)
Speed Command – The desired speed setpoint prior to local PAC task
modification such as linear accel/decel control, draw modification, trim
modification, etc. (Also see SPEED REFERENCE definition.)