| 700 / | HD | DATA PROCESSING: GENERIC CONTROL SYSTEMS OR SPECIFIC APPLICATIONS |
| 1 | DD | GENERIC CONTROL SYSTEM, APPARATUS OR PROCESS {15} |
| 79 | | .~ Having protection or reliability feature {3} |
| 80 | DD | .~.~> Warning or alarm |
| 81 | DD | .~.~> Self-test |
| 82 | DD | .~.~> Backup/standby |