Symbol 5311 from IEC 60417 - Title/Meaning: Multiframe Function/description: To indicate the use of pulses assembled in a multiframe.
Additional information: 
Published in: Supplement G, 1985
Own work using: iso.org/obp/graphics/grs/e263f993-abb2-48e2-85a1-f01b91077d19 200.png
Vectorization:  Mrmw