Scc Overhead Channel Setup - Comtech EF Data DMD-2050E Installation And Operation Manual

DMD2050E Universal Satellite Modem
3.20

SCC OVERHEAD CHANNEL SETUP

1. Set the Framing Mode (located under Mod and Demod Data Menus) to SCC. After doing
this, two new menus will appear to the right of the Framing Menu, for both the Mod and
Demod. The new menus will be:
SCC CTL RATIO
SCC INBAND RATE
2. Set the desired SCC control ratio:
SCC CTL RATIO {1/1, 1/2, 1/3, 1/4, 1/5, 1/6, 1/7}
This allows the user to simulate the framing used by the Satellite Control Channel Option
(Pass-Thru Mode only). The SCC CTL RATIO is the ratio of overhead in-band data to
synchronizing words.
3. Set the desired SCC in-band rate:
SCC INBAND RATE {300 to 115200}
This allows the user to request the rate of in-band data for the overhead channel. This
sets the overhead amount only. The actual amount of data that can be passed through
the overhead channel will be set under "ES Baud Rate" (see Step 6 below).
4. Under the Interface > General menus, locate the TX ASYNC MODE (menu).
5. Under the TX ASYNC MODE Menu, set the desired ES Interface type:
ES INTERFACE {RS-232, RS-485}
This allows the user to select the interface type.
6. Under TX ASYNC MODE Menu, set the desired baud rate for the ASYNC Port (J17). This will
be the baud rate that will pass through the overhead channel:
ES BAUD RATE {150 - 115200}
This allows the user to select the baud rate of the ASYNC port (J17) in SCC Mode.
7. Under TX ASYNC MODE Menu, set the desired ES BITS/CHAR:
ES BITS/CHAR {7,8}
This allows the user to choose between 7 or 8 bits of data.
8. Repeat Steps 4 through 7 under the RX ASYNC MODE (menu)
MN-DMD2050E Revision 2
Theory of Operation
3–67