331,222. Standard Telephones & Cables, Ltd., (Hatton, W., Vriendt, C. de, and Rousseau, E. J.). March 18, 1929. Divided on 331,204. Automatic exchange and metering systems.-A register controller comprises a multi-level translating switch SMB a. particular level in which is selected in accordance with the 1st 2 digits and which sets itself in accordance with the 2nd and 3rd. In a register-controller for use at the central office of a network of 20,000 lines divided into 100 line. groups and forming part of a 100,000 line network, each a, b, c, d terminal of SMB represents a particular 100-line group and the terminals corresponding to the groups, which need not be adjacent, forming an office are connected together. A switch SMC the terminals of which are jumpered to numerical bus bars and to relays producing special effects hunts for a terminal marked by the 10,000 register if the call is to go outside the network but otherwise for a position determined by the setting of SMB. In a modification not described in detail the function of SMC is taken over by SMB sets of levels being provided in place of the single levels a - - d. The register controller described controls zone metering. A similar circuit may be used for metering control only. Association of register controller with link. When the 1st finder switches through, a circuit is made for driving the 2nd finder Fig. 1. The finder is stopped by Ar<10> which is followed by Cr<10>, Br<10>, Dr<10>, Hr<10> (operated in series with the cut-off relay), Sr<10> (operated over the loop). Operation of Cr<10> energizes the starting relays Str<s>, Csr<6> and the idle switches PR start in search of the calling link under control of relays Rtr<6>. In the successful one Rtr<6> locks in series with Shr<6> which energizes Tcr to send back dialling tone. Rbr<6> interacts with SMA to move it one step from normal. Registration of number. Sr<10> repeats the digits to Ir<6> which repeats them in turn to registers SM10000 - - SMU. Series relay Slr<6> operating in conjunction with Rbr<6> causes the digit distributor SMA to move on after each digit. Cr<6>, Er<10 >pull up at the beginning of the 1st digit and lock. Dialing tone is cut off, and Cr<10> falls and releases Rtr<6>, Spr<6>. Tcr<6> however is held by Cr<6>. When two digits have been received. Jr<6> pulls up, energizing the even thousands relay Edr<6> if necessary, and completing the driving circuit under control of Tr<6> for the translator switch SMB to move to the group marked by the 1000's register. When the 1000's digit has been received J1r<6> pulls up and energizes T1r<6> which releases Tr<6> unless the 100's digit is 1 to enable. SMB to start again in search of the terminal marked by the 100's register, When SMB stops SMC hunts under control of Ttr<6> for the terminal marked' by SMB. Transmitting route code. When the routing switch SMC has been set, Tar' connects battery to the. a-wire to prepare the 1st selector, Bi<6> being connected to the b-wire and operating when the selector is ready, to energize Lr<6> and initiate the transmission of the digit. The power driven sending switch PI then makes a complete rotation, sending impulses as it goes from wiper Y until wiper X finds a marking potential from the m wiper of the routing switch, whereupon the trunk is bridged independently of Y by Nir<6>. After its 10th position wiper Y again bridges the trunk and wiper Z unlocks Nir<6>, Lr<6> and on reaching its final terminal energizes the 1st sequence relay Dr<6> to switch the marking from wiper m to wiper n of the rout. ing switch. The relapse of Lr<6> replaces battery and Br<6> on the a- and b-wires and two more routing digits are sent as before under control of wipers n, o (SMC) relay D1r<6>, switching the control from n to o. When Tare pulls up to initiate the transmission of impulses, ground is connected to wipers p, q (SMC) to operate such of the relays shown to the right of Fig. 4 as may be jumpered to the terminals on which the switch is standing. Assuming one of the terminal is jumpered to d, Lor<6> is operated over a conti<q>t of J3r<6> to delay the transmission of the tens digit until J3r' indicates that the units digit has been received. If Sk1r<6> is operated over e, D1r<6> is energized prematurely and the 2nd digit of the routing number is cut out, if over f, Dr<6>, D1r<6> are both operated and the 1st 2 digits are skipped. Sk2r' in a similar way causes the 2nd and 3rd routing digits to be skipped and Sk3r<6> the 2nd and 3rd routing digits and the hundreds digit, as well. <M>h6 if operated over k causes the transmission of the 1000's digit dialled instead of the 3rd of the routing digits. If -iNItr<6> is operated over i Lor<6> is operated also with the result described above. Spr<6> produces the same effect as Mtr<6> except that Rr<6> is operated to stop transmission and release the register controller after the 1000's digit has been sent. If a spare code is dialled the call is routed to an operator. Transmission of numerical digits, release of register controller and switch through of link. D2r<6>, D3r<6>, D4r<6> give control to the registers SM100 - - SMU the digits being sent in the same way as those of the route code. When all have been sent, Rr<6> is energized and unlocks Cr<6>. Holding relay Tcr<6> falls sluggishly. Lrr<6> pulls up to send the' registers home in turn and Rbr<6> then interacts with SMA until it also is home. Er<10> which is released by Rr<6> switches the. line wires through. The switch-through is delayed for a period fixed by the dimensions of the sending switch to ensure that battery in the final selector forming the " ready " signal shall have been removed from the b-wire since this would give the reply signal. Metering. For the purpose of controlling metering the p and g levels of SMC are jumpered to the points a, b, c. If a or c is connected. ground on p, q is extended over wipers f or e (PR) to operate Ir<10> or Kr<10> in the link circuit. If b is used Mmr<6> is operated and energizes Ir<10> and Kr<10>. In a local call neither of these relays is operated and the operation of S1r<10>, Nr<10> when the called party replies is followed by that of 1'r 10. Metering takes place when the calling party hangs up, releasing Dr<10>, Hr<10>, Br<10>, Fr<10>, a single impulse going back over e in the interval between the relapse of Hr<10>, Fr<10>. In external calls however the operation of one or both relays Ir<10>, Kr<10> prevents operation of Fr<10>. Clock impulses are connected to a time switch TA by Nr<10> and an impulse sending switch SMM is started and makes a single rotation sending 2, 3 or 5 metering impulses according to the state of relays Ir<1O>, Kr<10>. TA opens its contact A on moving off normal but recloses it at 3 minute intervals to cause further operations of SMM. Ten seconds before 12 minutes, C closes and gives a warning tone and at 12 minutes exactly B closes and breaks down the connection by grounding the e-wire. The register controller may be used simply for metering control in which case SMB may be operated directly by the hundreds digit unnecessary registers and other parts being of course omitted. Such a device is.- described in Specification 331,204.