Comtech EF Data OMS11 - Manual (Page 17)

Theory of Operation OMS11 1:1 Redundancy Switch
TM133 – Rev. 1.1 2-2
2.1.1 Operating Procedures
The OMS11 is designed to require minimal operator intervention and control during normal
operation. After initial setup, the unit should operate in a relatively ‘transparent’ manner,
providing trouble-free backup of the online Modems. The scope of this section is limited to
instruction on the various modes of control available to the operator. Refer to Section 3-1 for the
OMS11 Front Panel Controls and Indicators and Table 2-1 for a description of the Controls and
Indicators.
2.1.2 Configuring the OMS11
The redundancy switch must be properly configured prior to operation. Date interface type,
Remote communication type and remote baud rate must be set correctly to meet the users
needs. Configuring these options can only be done by removing the cover and accessing the dip
switches on the board. Appendix A of this manual gives specific information about the dip switch
settings for configuring the Terminal and Remote ports. If you need assistance with the settings,
contact Radyne customer service department.
2.1.3 Front Panel Controls (Refer to Figure 2-1)
The purpose of the ‘ENABLE’ pushbutton on the front panel is to reduce the risk of accidentally
changing the operating modes of the OMS11 by accidentally bumping any one of the front panel
pushbuttons. For any one of the front panel pushbuttons to function, the ‘ENABLE’ pushbutton
must be depressed simultaneously with the desired function pushbutton. Depress the ‘ENABLE’
pushbutton. This pushbutton must be depressed to allow the operator to proceed with any other
configurations. The ‘MANUAL’ LED should illuminate and the FAULT indicator may momentarily
flash. Under the MOD region of the front panel, depress ‘SELECT A’ to bring Modem ‘A’
modulator online. The green LED should illuminate. Under the DEMOD region of the front panel,
depress ‘SELECT A’ to bring modem ‘A’ demodulator online. The Green LED should illuminate.
The OMS11 should now be in backup mode with modem ‘A’ online.
2.1.4 Manual Mode
To manually select which Modem is to be placed online, simultaneously depress the ‘ENABLE’
pushbutton and the appropriate Modem ‘SELECT’ pushbutton. When a Modem selection is
made, the OMS11 enters Manual Mode to carry out the selection, and will not respond to either
modem’s Modem Fault signals until placed back into Auto Mode.
2.1.5 Auto Mode
To enable automatic backup in the event of a Modem failure, the OMS11 must be placed into the
Auto Mode. First, select which Modem that will be active by following the ‘Manual Mode’
procedure in the previous paragraph. To enter the Auto Mode, simultaneously depress the
‘ENABLE’ pushbutton and the ‘SELECT AUTO’ pushbutton. The OMS11 will then enter into Auto
Mode with the last selections made in Manual Mode. In the Auto Mode, the decision to switch
from one Modem to another is made automatically by monitoring the Fault signals from each
modem.
2.1.6 Power-Up Defaults
During power-Up, the OMS11 initializes itself to the last mode set by the operator on the front
panel pushbuttons.