Patent GB-855569-A (GB)
Title: Circuit arrangements for the transmission of teleprinter messages through duplex transmission paths, for example in links between line and radio systems
IPC: H03M13/51
Filed: 1958-02-21
Abstract: 855,569. Telegraph exchange systems. SIEMENS & HALSKE A.G. Feb. 21, 1958 [Feb. 21, 1957], No. 5800/58. Class 40(3). In a circuit arrangement for the transmission of teleprinter messages over duplex transmission paths, for example, over links between line and radio systems, in which a signal storage device for receiving teleprinter signals is provided in the transmitting channel of the arrangement and a selecting signal generator adapted to convert teleprinter signals into series of selecting impulses for operating selectors is associated with the signal storage device, a change-over means is adapted to connect the storage device into the receiving channel of the arrangement when a teleprinter connection is being built up so that dialling digits received over said receiving channel in the form of teleprinter signals can be converted into series of selecting impulses by the selecting signal generator. When a calling or busying signal is received over the radio link from a distant station, a relay in the code converter operates to change over contact et so that relay A is oppositely energized, contact a is changed over, and relay K energized simultaneously with the application of a positive pulse to the line KL2. If a free selector is found, a pulse over line KL1 operates a relay B to change over contact b so that relay S is operated over contacts b, kl, r1. At contact sl the relay A is changed over to the signal generator ZG and at s6 a busy criterion is sent via the code converter to the distant subscriber to indicate that dialling can commence. At contact s3 relay S locks up and at contacts s4, s5 relays X, HF are operated. At contacts hf1-h<SP>f</SP>5, the received and retransmitted pulses passing over contact s2, receiving magnet EM and over transmitter contacts 1-5 are applied to relays AG-EG controlling the conversion of 5-unit signals to digital selecting signals. At contact hf6 relay AN is energized and at contact an1 withholds the transmission of selecting pulses until all the dialling signals have been received, when a selected combination represented by a contact wk operates relay AL which at all opens the circuit of relay AN. The relay AL initiates operation of the transmitter controlling relays AG-EG according to the selecting characters so that the selecting signal generator ZG passes the corresponding digital pulses from contact i over released contact an1 to the relay A and over line KL2 to the line selectors. When the desired connection has been effected, a continuous positive signal over line KL1 energizes relay B so that slow-operating relay R is energized and at contact r2 operates relay MV breaking the locking circuit of winding II of relay S which now releases and effects the release of X and the delayed release of relay XH. Meanwhile relay WD is operated and at contact wdl connects a "who-are-you" transmitter CS to the relay A and the called line. The identification signal is passed over operated contact mvl and released contact s2 to the perforator magnet EM and then from the contacts 1-5 of the transmitter and contacts hf1-hf5 in the positions shown to the code converter leading to the radio transmitter. Contacts associated with the reperforator can be arranged to detect a selectioncancelling signal transmitted by the calling subscriber.