controller is removed for servicing.
h.
Controller shall be capable of being configured in field without
use of external computers, hand-held terminals, EPROM programmers
or other devices.
i.
Configuration changes and tuning adjustments shall be accomplished
by means of key pad on controller front. Controller digital
circuity shall be protected from power surges and spikes by
j.
Configuration shall be maintained in (2) removable battery backed
RAM chips. Failure in primary memory shall cause backup memory to
be downloaded automatically.
k.
Equipment Controller Self-Tuning PID Loop Routine
1. Self-Tuning PID Loops: Three methods of tuning PID Loops
shall be available: Manual, Automatic, and Adaptive. Provide
tuning utility allowing collection of data and process tuning in
real time.
2. The tuning utility shall display following information on
display upon operator request: Control loop being tuned, Input
process variable, Output control variable, setpoint of loop,
Integral reset interval, and Proportional band, Derivative rate
interval.
3. Above information shall be displayed on supervisory
workstation in graphic format with automatic scaling such that the
input and output variable are superimposed on a graph of time
versus variable. Program shall allow operator to affect output
variable by modifying setpoint, and tuning parameters, and view
results on display.
4. Automatic Tuning: Provide controller with on-line or manual
utility to disturb process. Utility shall monitor the results and
calculate new parameters for sample interval, Proportional band,
Integral gain, and Derivative gain. Utility shall be usable
during commissioning process to establish reasonable values, then
turned off.
5. Adaptive Tuning: Provide controller with on-line utility
which may run continuously.
6. Adaptive tuning shall be initiated automatically whenever
operator-defined change in the process input variable is detected.
Utility shall monitor process (control loop) after natural
disturbance, and automatically recalculate Proportional gain,
Integral gain, and Derivative gain. This utility shall be used to
keep a system tuned, as the equipment ages and occupancy and loads
l.
The tuning utility shall display following information on the CRT
upon operator request:
1.
Adaptive control is enabled or disabled.
2.
Maximum bump:
output step change required to produce a change
SECTION 15561A
Page 44