Patent GB-1067119-A (GB)
Title: A system for operating a plurality of remotely located elements
IPC: H04Q9/04
Filed: 1965-12-16
Abstract: 1,067,119. Electric selective signalling. INTERNATIONAL BUSINESS MACHINES CORPORATION. Dec. 16, 1965 [Dec. 29, 1964; Jan. 8, 1965], No. 53368/65. Heading G4H. A central station in a system for controlling a plurality of remote-station elements transmits to the remote-station for each element a respective first control pulse, an element being operated in response to its first control pulse together with a second control pulse produced by the remote-station in synchronism with the first pulse, operation causing an indicating pulse to be transmitted to the central station. In Figs. 1-3 (not shown), a rotating magnet (172) in the central station (Fig. 2, not shown), energizes centre-earthed coils (175-178) in turn, the first half of the first coil (175) transmitting a pulse over a line (84) to the remotestation (Fig. 1, not shown), where it energizes a write coil (14) to record a mark on a rotating magnetic disc (10). Each of the remaining central-station coils (176-178) when energized will pass a pulse from its first half through a corresponding element control switch (216- 218), if this is closed, via a transistor (230) with a selectively-tappable diode chain (234A- 234E) connected in its voltage supply for delay adjustment, to the line (84) to be applied in common to gating transistors (46-48) in the remote station. Concurrently, the mark recorded on the magnetic disc (10) is passing centre-earthed read coils (21-23) in turn. Each read coil (21-23) corresponds to a respective one of the gating transistors (46- 48) and when it is energized by passage of the mark, one half of it enables the transistor to pass the pulse from the control switch (216- 218) if present to operate a corresponding relay (71-73). This operates a corresponding element and passes a pulse induced in the other half of the corresponding coil (21-23) over the line (84) to the central station where it is gated to energize a corresponding relay (206- 208) by the pulse induced in the second half of the corresponding central station coil (176- 178). The relay lights a corresponding lamp. An erase magnet (12) is provided after the last read coil (23) for the magnetic disc (10). Each relay (71-73, 206-208) has an associated R.C. circuit (66-68, 201-203) so that once energized it remains energized for two cycles, preventing loss of a pulse through noise from affecting operation. The control swtiches (216-218) may be manually or computercontrolled. Figs. 4-5A (not shown) show a similar embodiment in which a permanent mark recorded on a rotating magnetic disc (300) at the remote station is read by a first pair of coils (304, 306) to cause two synchronizing marks to be recorded on a rotating magnetic disc (406) at the central station. The first of these, on passing respective coils (411-414), samples control switches (442, 444) in turn to produce pulses which are gated to the respective element-actuating relays (381-384) at the remote station by coils (311-314) sensing the permanent mark on the first disc (300). Two of the relays (381-384) correspond to each element, for on and off actuation respectively. When a relay (381-384) is energized it causes an indication mark to be recorded on the central-station disc (406). When the synchronizating marks on the latter disc (406) reach respective final coils (418, 420), the latter cause an AND gate (460) to reset indicating thyratrons (451-454) which are then selectively set under control of the recorded indication marks sensed by respective coils (411-414). It is mentioned that synchronizion could be done by remote and central synchronous motors with a common A.C. supply, and more than one remote station could be provided.