Optical Systems Design OSD139HS, Operator'S Manual

Page: 10 / 16

OPTICAL SYSTEMS DESIGN
DOC ID: 10117202
OSD139HS OPERATOR MANUAL
Page 10 of 16
The RS232 signals are connected to or from the external equipment as required via the 25 Pin D
connector of the OSD139HS. Table 3 identifies the connections for the OSD139HS configured in both
the DTE and DCE modes.
As previously 6V
DC
to +12V
DC
power may be fed to the unit via Pin 9 of the 25 Pin D
connector.
The optical fiber should be terminated with the appropriate optical connecters. Before connection,
inspect the end of the optical connecters to ensure that no dust or dirt is present as it could contaminate
the modem connecter and result in poor and degraded performance.
If it is necessary to clean the cable connecters, use isopropyl alcohol with a lint free tissue to remove
any contamination.
2.3 OPERATION
2.3.1
CONTROLS
The OSD139HS has only one control: the DTE/DCE switch located between the optical connectors.
This switch changes the OSD139HS between DTE and DCE modes.
FIGURE 5: DTE/DCE CONTROL
When the units are connected to a DTE host, the transmitting signal is on Pin 2 of the connector (data
into the modem) and the received signal is output by the modem on Pin 3 (data out from the modem).
The converse applies to a DCE host.
The pin differences between these two modes are detailed in section 1.5 PIN ASSIGNMENTS (page 7)
DTE DCE
DTE/DCE Switch