Grass Valley VM 3000 System Controllers v.7.4 - Manual (Page 756)

Glossary−8
PL board − PL 3000 Party Line Interface. Now obsolete.
PMEM − battery−protected memory.
polling − communication technique where central controller polls (addresses) each device on a party line in turn.
When so addressed, a particular device can then send or receive data without being interrupted.
polling name − a unique address assigned to a switcher control panel. When transmitted by the polling and
control card, allows communication between that panel and the switcher matrix.
PPM − peak program meter.
protect − on Jupiter control panels with a PROTECT button: after a given source has been switched to a given
destination, and PROTECT is pressed, the source for that destination can then be changed only at the panel
which protected the output. Note that a panel can only protect
LEVELS that are assigned to the panel during
configuration. See also LOCK , and FORCE UNPROTECT/UNLOCK .
primary status instruction − in Jupiter systems, a configuration technique used in the CP Input set for display of
SPLIT MNEMONICS . Indirect (“I”) entries are used to point to a primary (“P”) entry. The primary entry in turn
points to the desired mnemonic for that level.
refresh − continuous repetition of switching instructions and confirmation of crosspoint status. Reports any
interruption of service — for example, if crosspoint board is removed. When board is replaced, automatically
restores previous switch instructions.
repeater − a device for connecting two LAN segments.
remote PC −a PC on a Jupiter LAN in addition to the PC used as the file server. Can be used for auxiliary tasks such
as remote LOGGING .
remote switcher −a non−Thomson distribution switcher under Jupiter control.
retained level − see STICKY LEVEL.
reverse switching −reverse switching is used in RS−232/422/423 data switchers where one level is used to switch
data from a controlling device (such as an editor) to a controlled device (such as a VTR); a second level is used
to return data to the controller. The return path is switched automatically by the control system.
RS−422 − EIA standard which defines the electrical characteristics of balanced voltage digital interface circuits.
More rugged than the earlier RS−232 standard, which employs unbalanced voltages. This standard does not
specify a connector type. While the Jupiter VTR / control panel bus and CC 2010 matrix (crosspoint) bus are
both based on the RS−422 standard, the VTR / control panel bus uses 9−pin D connectors and the CC−2010
matrix bus uses 15−pin D connectors.
RS−422 bus − see SERIAL BUS .
S board − SC 3000 Serial Control Interface. Now obsolete.
salvo − single−command switching of source(s) to multiple destinations.