Specifications

Synergy Nano Technical Manual, Revision -
Page 52
Reset Constant
Reset controls the integration error. The larger this value the faster the integration term will change.
Increasing reset adds gain to the system. A lower Reset slows the controller response and
increases stability.
Rate Constant
The Rate is used to scale the rate of change with time and controls the calculation of the derivative.
The derivative aids in canceling out the oscillation that normally occurs with PID calculations. It, in
effect, tries to put toughs in the line when the calculations are causing crests and tries to put crests in
the line when the calculations are causing troughs. The derivative acts like a large mass, it doesn’t
want to move. A higher Rate increases this mass and makes the program run slow and smooth. A
low Rate allows the temperature to change faster but causes more instability.
Cycle Time Constant
Cycle Time controls the time period of the proportional cycle. The output goes through one on and
off cycle each period. Faster Cycle times reduce the size of steps on the output but may put more
strain on the output devices such as valves. Slow cycle times may increase the size of steps but can
also increase the life span of certain chamber hardware.
Rate Band Constant
Rate Band is not currently used.
Cascade Control
CASCADE \ PID \ SETUP DIRECTORY
 Enabled  Settings  PIDs
(Screen Editor) (Screen Editor) (Screen Editor)
♦ Enabled
♦ Disabled
♦ Sensor Select
♦ Cascade High Limit
♦ Cascade Low Limit
♦ Cascade High Deviation
♦ Cascade Low Deviation
♦ Prop. Band
♦ Reset
♦ Rate
♦ Cycle Time
♦ Rate Band
Cascade control is a control system method in which the temperature setpoint and actual readings are taken
from the both the air temperature and the unit-under-test. These settings and readings are combined in the
PID calculations and offer the user greater speed and more accurate UUT temperature control during the
test. Using the Cascade feature allows the operator to control the chambers processes to bring the Unit
Under Test to the desired temperature, rather than just the air temperature. Cascade control provides
greater test accuracy in addition to faster and more efficient ramps and soaks.
Because the Cascade control is a powerful feature of the Synergy Nano, we have dedicated a separate
section for its discussion. See Section 14 Cascade Temperature Control
for a detailed and complete
description of the Cascade feature.