Circuit arrangement for PCM telecommunication facilities

A switching circuit for PCM long distance exchange facilities, in which a plurality of synchronous pulse clock controlled transmitters transmitting binary coded information have simultaneous access to a common transmitting channel and in which provision is made for the interruption of two or more simultaneous transmissions after simultaneous transmission by two or more transmitters, each of said transmitters including:

• (a) means for initially at the beginning of a transmission always transmitting its own binary coded transmitter specific address;
• (b) means for providing that the information transmitted by the transmitter flows together bit-wise when transmitted by two or more transmitters simultaneously;
• (c) means for providing that when inequality of binary characters transmitted by two or more transmitters in coequal time-slots and flowing together the character of one type of two possible types of binary characters asserts itself against the character of the other type;
• (d) such that the information flowing together is transferred back to the transmitters;
• (e) including means for each transmitter to compare bit-by-bit the information instantaneously transmitted with the information received back at the corresponding point in time;
• (f) means for providing that each transmitter in the event that the character received back at said corresponding point in time is a character of one type, and the character transmitted with coequal time-slots is one of the other type the transmission is interrupted, comprising;
• pulse clock controlled converters between the transmitters and the transmission channel for renewing the binary characters at the transmitting channel;
• and
• a test channel over which the transmitters transmit their binary characters;
• whereby the binary characters on their way to the test channel flow together, are transmitted between two clock pulses and are combined at the test channel and coupled back to the transmitter such that a potentially required interruption of transmission with certainty occurs within the time interval between two clock pulses.