DETAILED DESCRIPTION In elaborating on the particulars of the illustrative embodiment, it is helpful to visualize and discuss a layout of the complete system in an overview fashion.
Accordingly, FIG.
1 depicts, in combined schematic, block diagram and pictorial form, two units, namely, master unit 100 and remote unit 200, comprising the basic tester, along with necessary connecting means to interface each unit to cable 500 under test.
The 501,502 pair is a good pair prepared to undergo testing, as will be explained shortly.
Pair 503,504 is transposed with pair 505,506, whereas pair 507,508 is reversed, and all are awaiting testing.
To enable units 100 and 200 to operate in synchronism, a set of leads, designated as control channel 175, serves as telemetry and runs between the master and remote units.
Oftentimes control channel 175 is provided by pairs that either have not been affected by the work activity or are manually prechecked.
Channel 175 provides pair address information to remote decoder 210 so that both master decoder 130 and remote decoder 210 can operate, respectively, access switch 140 and termination switch 220 in synchronism.
In order to provide an electrical reference point essentially common to both units 100 and 200, continuous metallic layer 511 comprising the sheath surrounding cable 500 is typically utilized.
Lead 176 connects one end of layer 511 to unit 100, whereas lead 276 connects the other end of layer 511 to unit 200.
At the location of master unit 100, conductors 501, 502, .
.
.
, 508 are connected, respectively, to master unit leads 1011, 1012, .
.
.
, 1018 emanating from the unit, using interposed connectors 310 and correspondingly mated connectors 311.
Similarly, pairs of connectors of the 310,311 type are used to join conductors 501, .
.
.
, 508 to leads 2011, .
.
.
, 2018 at the remote location in the proper sequence presuming no errors.
Testing commences whenever sequencer 110 is reset, under operator initiative, so that testing and sequencing may begin on the first pair 501,502
|
CPUs 
