Changing The Jumper Settings - 3Com NETBUILDER II Installation Manual

Changing the
Jumper Settings
I f you change a port setting from DTE to DCE, you must set the -PATH Service CLock
parameter from External to Internal for that port. Refer to the CLock parameter in the "Path
Service Parameters" chapter in the NETBuilder Family Bridge/Router Reference Guide for
instructions.
This section describes how to change the jumpers to enable the module to connect to
DTE devices. Skip this section if you are using only DCE devices.
The jumpers on the module are factory-set to support connecting the module ports to
DCE devices with an RS-232 3-Port cable. Typical DCE devices are modems, ISDN
terminal adapters, and CSU/DSUs.
To connect one or more of the connectors on the 3-Port cable to a DTE device, such as
a cluster controller or a mainframe computer, change the jumper settings as follows:
1 Remove the jumper located in the E-4 position (see Figure 1-1).
2 For the ports you want to connect to DTE devices, move the jumpers from the DTE
row of pins to the DCE row of pins (see Figure 1-1).
CAUTION: When changing jumper settings on the module and when cabling the
module to devices, be aware that when the RS-232 3-Port cable is connected to the
module, the positioning of the three hydra cables carrying the port signals are not
visually in a direct or expected line with the location of the jumpers on the module to
which the signals correspond. (See Figure 1-1.)
When any one of the three ports on the module are changed from DTE to DCE, the
test-mode configuration is lost for all three ports.
Figure 1-1 shows the jumper in the E3 slot for port J3(C) set to DCE and shows two
ports set to DTE.

Changing the Jumper Settings

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