Private automatic branch exchange service circuit complex

Claim 2

A service circuit complex for use in a private automatic branch exchange having an operator service link network and a plurality of various type trunks for different type calls comprising: groups of various type service circuits for servicing the different type calls, each group containing only the same type of service circuit and having means for selecting one available service circuit at a time within the group and common control means for connecting a service circuit to a trunk through the operator service link network in response to a request for that type of service circuit from one of the trunks, said common control means including a trunk scanner for sequentially scanning the various trunks for service requests and responding to a service request by stopping and applying a request signal to the service circuit groups containing the requested service circuit type and a system timer for sequentially enabling said service circuit groups in an arrangement whereby a connection between a trunk and a selected service circuit can only be made while the group containing the service circuit is enabled and a request signal is applied thereto.

Claim 3

The service circuit complex of claim 1 wherein service requests from the trunks for different type service circuits are applied to said trunk scanner on different leads.

Claim 4

The service circuit complex of claim 2 wherein said selecting means is an individual rotary associated with each service circuit group for preselecting an available service circuit within the group to await connection to a trunk when a request signal is received and the service circuit group is enabled.

Claim 5

The service circuit complex of claim 3 wherein said trunk scanner includes monitor means for monitoring said rotaries to determine if at least one of each type of service circuit is available and means responsive to receipt of a service request coincident with an indication from said monitor means of an available service circuit of the type requested for stopping said trunk scanner at the trunk generating the request.

Claim 6

The service circuit complex of claim 2 wherein said sequential enabling consists of individual enabling time slots within a repetitive time sequence whereby each service circuit group is enabled during a different enabling time slot and the generation of a request signal is synchronized to the beginning of the enabling time slots.

Claim 7

The service circuit complex of claim 2 wherein said service circuit groups include at least one group of dial pulse acceptors, one group of transfer circuits and one group of loop circuits the latter being associated with an individual position circuit and the trunks include at least one trunk interfacing the branch exchange with other exchanges for connection to any one of said service circuits, at least one attendant trunk for connecting a local station within the branch exchange to an operator via said position circuit and one of said loop circuits and at least one access trunk for connecting said position circuit via one of said loop circuits to a local station within the exchange.

Claim 8

The service circuit complex of claim 6 wherein said interfacing trunk means applies to said trunk scanner a first service request for a dial pulse acceptor immediately upon sequence of the trunk by another exchange which is gated with the next enabling time slot after receipt of said first service request to inhibit the generation of request signals for transfer and loop circuits by said trunk scanner until the service request for a dial pulse acceptor is satisfied.

Claim 9

The service circuit complex of claim 7 wherein said interfacing trunk means appliEs to said trunk scanner a second service request when next scanned by said trunk scanner after the generation of said first service request, said second service request causing said trunk scanner to stop upon indication of an available dial pulse acceptor.

Claim 10

The service circuit complex of claim 8 wherein said system timer generates one sequence of enabling time slots for said transfer and loop circuit groups and a second sequence of enabling time slots coincident therewith for said dial pulse acceptor groups and wherein said first service request inhibits the generation of the first mentioned enabling time slots until after the service request for a dial pulse acceptor is satisfied.

Claim 11

The service circuit complex of claim 6 including a queue circuit for receiving and servicing loop circuit requests in the order in which they are received from said interfacing and attendant trunks by applying a loop circuit request signal to said trunk scanner when the trunk being scanned is the same as the next trunk slated for servicing in said queue circuit.

Claim 12

The service circuit complex of claim 3 wherein each of said rotaries comprises a ring counter having a different output lead connected to each service circuit within its associated group to which an enabling signal is sequentially applied and a monitor circuit connected to said leads and to said service circuits for receiving signals indicating the availability of each service circuit so that when the enabling signal is applied to the lead of an available service circuit it is fed back by said monitor circuit to said ring counter to stop the operation thereof.

Claim 13

A trunk service circuit complex for use in a private automatic branch exchange comprising: groups of various type service circuits, each group containing only the same type of service circuits; a plurality of trunks; a switching network for connecting any one of said trunks to one of said service circuits; means in each of said trunks for generating service requests indicative of the type of service circuit to which connection is to be made; means for scanning said trunks, said means being stopped at a trunk by a service request for marking the trunk and applying a corresponding request signal to all of the groups having the requested type of service circuit; timing means for sequentially enabling said service circuit groups in an arrangement whereby a service circuit is marked for connection to a trunk only when its group is enabled and a request signal is applied thereto; individual means associated with each group for selecting an individual available service circuit therein for marking, and path finding means responsive to the marking of one of said trunks and one of said service circuits for effecting a connection therebetween via said switching network.

Claim 14

A trunk service circuit complex for use in a private automatic branch exchange comprising: groups of various type service circuits, each group containing only the same type of service circuits; a plurality of trunks; a switching network for connecting any one of said trunks to one of said service circuits; means in each of said trunks for generating service requests indicative of the type of service circuit to which connection is to be made; means for scanning said trunks, said means being stopped at a trunk by a service request for marking the trunk and applying a corresponding request signal to all of the groups having the requested type of service circuit; timing means for sequentially enabling said service circuit groups in an arrangement whereby a service circuit is marked for connection to a trunk only when its group is enabled and a request signal is applied thereto; individual means associated with each group for selecting an individual available service circuit therein for marking, and path finding means responsive to the marking of one of said trunks and one of said service circuits for effecting a connection therebetween via said switching network.

Claim 15

The trunk service circuit complex of claim 14 wherein said service circuit groups include at least one group of dial pulse acceptors, one group of transfer circuits and one group of loop circuits the latter being associated with an individual position circuit and the trunks include at least one trunk interfacing the branch exchange with other exchanges for connection to any one of said service circuits, at least one attendant trunk for connecting a local station within the branch exchange to an operator via said position circuit and one of said loop circuits and at least one access trunk for connecting said position circuit via one of said loop circuits to a local station within the exchange.

Claim 16

The trunk service circuit complex of claim 13 wherein said selecting means is an individual rotary associated with each service circuit group for preselecting an available service circuit within the group to await connection to a trunk when a request signal is received and the service circuit group is enabled.