Watlow Series 1500 - Manual (Page 85)

Glossary
This glossary includes general thermal system control terms; not all are used with the Series 1500.
Actual display data: Displayed information which gives the operator/programmer real or “actual”
data, i.e., actual time of day, actual process temperature, or actual process
relative humidity, etc. See “Programmed display data.”
Alarm:
Anti-reset:
Automatic prompts:
A signal, generated by the Series 1500, warningthe
has exceeded or fallen below the alarm set point.
operator that the process
Control
band. that inhibits automatic reset action outside of the proportional
Data entry points where a microprocessor-based control “prompts” or asks the
operator/programmer for information input. A Series 1500 prompt has two
letters.
Auxiliary outputs: ON/OFF outputs per channel, one of which may be designated as an alarm.
An unprogrammed step will take auxiliary output status from the programmed
step to that just prior to it.
Auto-reset: Same as “reset” and “integal.” Control action that automatically eliminates
offset, or “droop,” between set point and actual process temperature.
Change Data Mode: (CHG DATA) - Set up the program step information for the Serles 1500,
including step type, set points, step duration, "wait for" or “jumploop”
conditions, and auxiliary output status.
Change Parameter Mode: (CHG PARA) - Set up the system step information for the Series 1500, including
real time, high and low range limits, alarm types, alarm points, PID parameters,
and RS-422 address.
Channel:
Closed loop:
A distinct electronic control bop or path for reading input data
communicating information to an output device or devices. and
Control system that has a sensing device for process variable feedback.
Cold junction: Point of connection between thermocouple wires and the electronic instrument.
Cold junction
compensation: Electronic means used to subtract the effect of the cold, or reference junction
temperature from a thermocouple’s electro-chemical circuit.
Cold start: A “clean,” or completely cleared-of-user-programmed information, start-up
condition. In the Series 1500, powering up with DIP Switch #6 in the “ON”
position gives a “Cold Start.”
Cycle time: The time necessary to complete a full ON-through-OFF period in a time
proportioning control system.
DATA: Values (for a specific Series 1500 parameter) which appear in the control’s
DATA display. DATA may be changed in the CHG DATA mode with the UP/
DOWN keys.
Dead Band:
Glossary, Appendix
Represents the area where no heating or cooling takes place in a heat/cool
proportional control.
WATLOW Series 1500 User’s Manual 85