simplex printer

simplex printer

(communications)A term applied by Western Union TelegraphCompany to teletypewriters that are not part of amultiplex system. They usually provided for alternatetransmission in both directions. If working simplex orhalf-duplex, what was keyed in at the keyboard would betyped out at the printing portion. If working full-duplex,sending would be blind as the printing portion was being usedonly for reception.