---
task: Create sub-items (integrator, min-max)
version: R1.03
source: IM 36K10G10-01EN §3.1.5, §3.2.3; practiced with CI-Eng-Sample 2026-09-30
status: verified
---

# Sub-items

A sub-item hangs under an item (`<Section>.<Tag>.<Sub>`) and processes the main item's value.
Types: `Integrator`, `Min-Max`, `Pulse`, `Rate-of-Change`, `Typeless`. Sub-items cannot connect
to equipment, cannot have sub-items, and are **not** blocked when the main item is blocked.

Quick load (`SUB_ITEM_DF`; the main item must exist):

```
@FIELDS
NAME,DESCRIPTION,SUB_TYPE,TIME_UNIT,MIN_MAX

@SUB_ITEM_DF
"CI-Eng-Sample.PUMP1.RUNNING.RUN_SECONDS","Pump 1 running time (seconds)","Integrator","",""
"CI-Eng-Sample.TANK1.LEVEL.MAX","Tank 1 maximum level","Min-Max","","Maximum"
```

Load with `dssqld -i <file>.qli -l <file>.qlo`; remove with a `NAME`-only file and `dssqld -r`
(before removing the main item).

## Behaviour (verified)

- **Integrator** adds *value × seconds*: with the main item at 1 it grows by 1 per second.
  `TIME_UNIT` (e.g. `Hour`) made no difference (`knowledge/issues.md` ISS-010); to show hours,
  divide by 3600 where the value is used.
- **Min-Max** with `MIN_MAX` = `Maximum` (or `Minimum`) keeps the highest (lowest) value
  written to the main item: writing 30, 70, 50 gave 70.
- `TIME_UNIT` (Second, Minute, Hour, Day) belongs to Rate-of-Change (from docs, not practiced).

Example files: `examples/CI-Eng-Sample/02b_sub_item_df.qli`, `90b_remove_sub_item_df.qli`.