Glossary

Alarm Delay - the time delay between the detection of the alarm	condi-
tion and the initiation and indication of the output action.

Alarm Inhibit - prevents low setpoint alarm activation during cold startup applications.

Bias - allows the operator to compensate for any difference between sensor temperature and the point to be measured. The process display and set- point will be offset by the value entered in the Bias parameter in the input menu. Ex: Desired temperature is 150 degrees. Sensor is adjacent to heater and reads 50 degrees higher than the actual process temperature. Enter bias of -50. Enter setpoint of 150. Process will display 150 even though sensor will be measuring 200 degrees.

Blanking - controls the time the setpoint value display remains on. After the set time, the setpoint value display turns off. Pressing any button causes the setpoint value display to reappear for the selected time interval.

Cycle Time - The period of time in which the controller’s output completes an on-off cycle (Proportional Output Type only).

Example: Output type = Mechanical relay Cycle time = 10 seconds Output power = 50%

Controller output = 5 seconds closed, 5 seconds open

Deadband - In On/Off temperature control, it is the band above or below the setpoint where there is no output action. It has the effect of moving the apparent setpoint.

Derivative (rate) - Adjusts the controller gain quickly in response to load changes.

Failsafe State - designates the percentage of power output that the con- troller defaults to after it detects a loop break condition and after the loop break time has elapsed.

Filter (in Display menu) - changes the filtering speed for the process value display only. It does not affect control. This parameter is mainly used to slow down the flickering of the display when the decimal position chosen is greater than zero.

Filtering (in Input menu) - sets the time period over which the process value is averaged.

Highest Reading - records the highest process value read by the controller. It may be reset to zero by using the Raise or Lower arrow keys. Hysteresis - In On/Off temperature control, hysteresis represents the band where the output changes state from deactivated to activated. It prevents chattering around the setpoint and prevents rapid output cycling.

Integral (automatic reset) - slowly adjusts the position of the Proportional Band (range of power output) to eliminate offset error.

Loop Break - a condition where the input is not changing or responding properly to the output action. This could be caused by a thermocouple or