
Original — December 1991
UM4.6:CS6003
Glossary-1
Glossary
A
Absolute Alarm An alarm which is triggered when the signal that is being monitored
reaches an absolute level, as opposed to a level which is relative to
another value. High Alarms and Low Alarms are types of absolute
alarms. [See Deviation Alarm.]
ACIA Acronym: Asynchronous Communications Interface Adapter
ACK Abbreviation: Acknowledge
Acknowledge (ACK)
To respond to an alarm or other indicator of an unusual condition.
Operators of PROVOX systems can acknowledge alarms themselves.
Optionally, in many situations, the system can acknowledge alarms
automatically.
ac
2
Trademark of Fisher Controls for the product line of analog control
instruments that preceded the PROVOX product line. The trademark is
an acronym for analog control center.
A/D Acronym: Analog-to-Digital, or Analog to Digital Converter
Adaptive Gain A type of primary control algorithm which allows the proportional gain to
change based on the value of an analog signal, a discrete signal, the
process variable, the implied valve position, or the process error. (The
process error is the difference between the PV and SP values.)
ADC Acronym: Analog to Digital Converter
Address One or more integers arranged to identify the location of a device or
logical unit of an instrumentation system. In PROVOX systems, address
values identify such things as data highway, device, file, card, and
channel.
AI Acronym: Analog Input
Alarm Deadband
The amount by which the PV value must return within normal limits for
the system to clear an alarm. (For example, if the system activates an
alarm as soon as the PV value exceeds 100 percent, but the deadband
is 5 percent, the system would not clear the alarm until the PV value
drops to 95 percent.)
Abs - Ala
Glossary
Komentarze do niniejszej Instrukcji