24
PRO SWITCHING SYSTEM
Figure 3-2. Three-Cavity Patching.
When you insert a patch cord into the MON cavity, it is connected to the circuit
between the DTE and the DCE. This is a bridge connection, and the circuit is not
broken. You can monitor the signals.
When you insert a patch cord into the COMP cavity, the circuit is broken and
the cord is connected to the DTE. You can test the DTE.
When you insert a patch cord into the MODEM cavity, the circuit is broken and
the cord is connected to the DCE. You can test the DCE.
Three-cavity patching is available for use with the following interfaces: RS-232,
V.35, and RS-530.
3.1.3 F
OUR
-C
AVITY
P
ATCHING
These cards have A/B switching and four patch cavities: COMP, MODEM, MON A,
and MON B. Figure 3-3 shows four-cavity patching when the switch is in the A
position. Normally, the appropriate DTE is connected to the DCE.