Symbol 5310 from IEC 60417 - Title/Meaning: Frame Function/description: To indicate the use of pulses assembled in a frame.
Additional information: 
Published in: Supplement G, 1985
Own work using: iso.org/obp/graphics/grs/407504c2-fa60-4153-b0a6-28e153cf7884 200.png
Vectorization:  Mrmw