| 700 / | HD | DATA PROCESSING: GENERIC CONTROL SYSTEMS OR SPECIFIC APPLICATIONS |
| 1 | DD | GENERIC CONTROL SYSTEM, APPARATUS OR PROCESS {15} |
| 28 | DD | .~ Optimization or adaptive control {13} |
| 40 | DD | .~.~ Plural modes {2} |
| 41 | | .~.~.~ Proportional-Integral (P-I) {1} |
| 42 | DD | .~.~.~.~> Proportional-Integral-Derivative (P-I-D) |