B&R Industries Automation PC 620, User Manual

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Appendix A • Glossary
Automation PC 620 User's Manual V 1.90
QVGA
Abbreviation for Quarter Video Graphics Array. Generally a screen resolution of 320 × 240
pixels.
QUXGA
Abbreviation for Quad Ultra Extended Graphics Array. Generally a screen resolution of 3200 ×
2400 pixels (4:3). Quad implies the 4x greater pixel resolution compared to the UXGA.
QWUXGA
Abbreviation for Quad WUXGA; Generally a screen resolution of 3840 × 2400 pixels (8:5, 16:10).
RAM
An abbreviation for »Random Access Memory« A semiconductor memory which can be read or
written to by the microprocessor or other hardware components. Memory locations can be
accessed in any order. The various ROM memory types do allow random access, however they
cannot be written to. The term RAM refers to a more temporary memory that can be written to
as well as read.
ROM
An abbreviation for »Read-Only Memory« A semiconductor in which programs or data have
already been permanently stored during the production process.
RS232
Recommended Standard Number 232. Oldest and most widespread interface standard, also
called V.24 interface; all signals are referenced to ground making this an unbalanced interface.
High level: -3 ... -30 V, Low level: +3 ... +30 V; cable lengths up to 15 m, transfer rates up to 20
kbit/s; for point-to-point connections between 2 participants.
RS422
Recommended Standard Number 422; Interface standard, balanced operation resulting in
increased immunity to disturbances. High level: 2 ... -6 V, Low level: +2 ... +6 V; 4-wire
connection [inverted/not inverted], cable lengths up to 1200 m, transfer rates up to 10 Mbit/s, 1
sender can carry out simplex communication with up to 10 receivers.
RS485
Recommended Standard Number 485; Interface standard upgraded from RS422; High level: 1.5
...-6 V, Low level: +1.5 ... +6 V; 2-wire connection [half duplex operation] or 4-wire connection
[full duplex operation]; cable lengths up to 1200 m, transfer rates up to 10 Mbit/s. Up to 32
participants can be connected to an RS485 bus [sender/receiver].
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