Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

1⊓

IEC

IEC non-retriggerable monostable

The non-retriggerable monostable produces one output pulse of fixed duration when triggered. Further triggers during that pulse have no effect. IEC drawings show the qualifier 1 with a single pulse shape inside the outline, and timing component connections are shown as non-logic inputs.

Drawing use

Schematic

Application

Logic & signals

Reference family

IEC / Manufacturer

Form evidence

Rectangular element with the 1 and single-pulse qualifier. Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier.

A distinction that matters

The retriggerable monostable extends its pulse on each new trigger and is drawn without the 1.

Full referenceAdd to legend

⊓

IEC

IEC retriggerable monostable

The retriggerable monostable is marked with the single pulse shape without the preceding 1. Each trigger during the output pulse restarts the timing, so the output remains active as long as triggers arrive more often than the set period.

Drawing use

Schematic

Application

Logic & signals

Reference family

IEC / Manufacturer

Form evidence

Rectangular element with the single-pulse qualifier only. Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier. The counterpart is the matching functional concept; no equivalence of every detailed standard graphic is asserted.

A distinction that matters

The non-retriggerable form has the 1 qualifier and ignores triggers during the pulse.

Full referenceAdd to legend

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.