Watlow CAS200 - Manual (Page 117)

Watlow Anafaze 105
Glossary
A
AC
See Alternating Current.
AC Line Frequency
The frequency of the AC power line measured
in Hertz (Hz), usually 50 or 60Hz.
Accuracy
Closeness between the value indicated by a
measuring instrument and a physical constant
or known standards.
Action
The response of an output when the process
variable is changed. See also Direct action,
Reverse action.
Address
A numerical identifier for a controller when
used in computer communications.
Alarm
A signal that indicates that the process has
exceeded or fallen below a certain range
around the setpoint. For example, an alarm
may indicate that a process is too hot or too
cold. See also:
Deviation Alarm
Failed Sensor Alarm
Global Alarm
High Deviation Alarm
High Process Alarm
Loop Alarm
Low Deviation Alarm
Low Process Alarm
Alarm Delay
The lag time before an alarm is activated.
Alternating Current (AC)
An electric current that reverses at regular
intervals, and alternates positive and negative
values.
Ambient Temperature
The temperature of the air or other medium
that surrounds the components of a thermal
system.
American Wire Gauge (AWG)
A standard of the dimensional characteristics
of wire used to conduct electrical current or
signals. AWG is identical to the Brown and
Sharpe (B&S) wire gauge.
Ammeter
An instrument that measures the magnitude
of an electric current.
Ampere (Amp)
A unit that defines the rate of flow of electric-
ity (current) in the circuit. Units are one cou-
lomb (6.25 x 1018 electrons) per second.
Analog Output
A continuously variable signal that is used to
represent a value, such as the process value or
setpoint value. Typical hardware configura-
tions are 0-20mA, 4-20mA or 0-5Vdc.
Automatic Mode
A feature that allows the controller to set PID
control outputs in response to the Process Vari-
able (PV) and the setpoint.
Autotune
A feature that automatically sets temperature
control PID values to match a particular ther-
mal system.
B
Bandwidth
A symmetrical region above and below the set-
point in which proportional control occurs.
Baud Rate
The rate of information transfer in serial com-
munications, measured in bits per second.
Block Check Character (BCC)
A serial communications error checking
method. An acceptable method for most appli-
cations, BCC is the default method. See CRC.
Bumpless Transfer
A smooth transition from Auto (closed loop) to
Manual (open loop) operation. The control out-
put does not change during the transfer.