Testing of echo blocks in TDM telecommunication system - using decentralised process-controller assembling test bit patterns and check output relation to pattern

摘要

For the testing of a particular operation of an echo-block, the levels corresponding to that operation are set up in the receive path (XE) and the send path (XS). Then forms a decentralised processor controller, a particular test bit pattern is sent out channelwise via the group coupler onto the receive path of the echo-block, and via the line interface unit is fed either unaltered or inverted to the send path (XS) of the corresponding channel of the echo-block. The bit pattern accordingly appearing on the send path is fed back again to the decentralised processor, and by comparison with a reference pattern the correct behaviour of the echo-block is evaluated. USE - In PCM-TDM exchange installations.