Method of operating file gates in an exchange for PCM words

Claim 2

In an exchange wherein PCM words in a time divison multiplex format are transferred from incoming transmission links to a first time stage and from the first time stage, during time slots, on files via a space stage to a second time stage and hence to outgoing transmission links a method for operating the file gates of the exchange comprising the steps of dividing Each time slot into two parts, transmitting to an address register in the space stage during the first part of a time slot an address allotted to one of the files outgoing from the space stage, transmitting to the space stage during the second part of a time slot the actual PCM word, storing in said address register said address and decoding the contents of said address register to generate one of a plurality of control signals, each of said control signals being associated with a particular address during the respective time slot, and activating, by means of the generated control signal an associated file gate which connects the file on which the address and the PCM word have been transmitted to the outgoing file identified by the address.

Claim 3

Method according to claim 1, characterized in that the PCM words and the addresses are transmitted through the stages of the exchange in parallel form.

Claim 4

In a PCM exchange comprising a first time stage, a space stage and a second time stage to and from which PCM words are received and sent out on transmission links in a time division multiplex system and through which stages each of the PCM words during a time slot is transmitted on files from the first time stage via the space stage to the second time stage, the incoming and outgoing files of the space stage forming rows and columns in a matrix which at every crossing point includes a file gate whose activation produces a connection between the files associated with the crossing point, apparatus for operating the file gates, said apparatus comprising: a clock generator means for generating two successive activation pulses during each time slot; associated with the first time stage, address memories for storing addresses allotted to files outgoing from the space stage, scanning devices cooperating with the address memories for reading one of said addresses in every time slot, and gating means for controlling, on the files incoming to the space stage, during the first activation pulse in each time slot the transmission of the addresses read from the address memories and during the second activation pulse in each time slot the transmission of the PCM words; and associated with the space stage, a plurality of blocking means, each of said blocking means being connected to an incoming file for blocking the PCM words transferred during the second activation pulses, a plurality of address registers, each of said address register being connected to a blocking means for storing the addresses transferred during the first activation pulses, and a plurality of decoder means, each of said decoder means being connected to one of the address registers for decoding said addresses, each of the outputs of a decoder means being connected to an address-responsive file gate of those file gates which are connected to the incoming file that transferred the address which activated with said decoder means output.

Claim 5

In a PCM exchange comprising a first time stage, a space stage and a second time stage to and from which PCM words are received and sent out on transmission links in a time division multiplex system and through which stages each of the PCM words during a time slot is transmitted on files from the first time stage via the space stage to the second time stage, the incoming and outgoing files of the space stage forming rows and columns in a matrix which at every crossing point includes a file gate whose activation produces a connection between the files associated with the crossing point, apparatus for operating the file gates, said apparatus comprising: a clock generator means for generating two successive activation pulses during each time slot; associated with the first time stage, address memories for storing addresses allotted to files outgoing from the space stage, scanning devices cooperating with the address memories for reading one of said addresses in every time slot, and gating means for controlling, on the files incoming to the space stage, during the first activation pulse in each time slot the transmission of the addresses read from the address memories and during the second activation pulse in each time slot the transmission of the PCM words; and associated with the space stage, a plurality of blocking means, each of said blocking means being connected to an incoming file for blocking the PCM words transferred during the second activation pulses, a plurality of address registers, each of said address register being connected to a blocking means for storing the addresses transferred during the first activation pulses, and a plurality of decoder means, each of said decoder means being connected to one of the address registers for decoding said addresses, each of the outputs of a decoder means being connected to an address-responsive file gate of those file gates which are connected to the incoming file that transferred the address which activated with said decoder means output.