Scc Overhead Channel Setup - Radyne OM20 Installation And Operation Manual

OM20 Universal Outdoor Modem
Example 1:
than In-Band Rate)
Example 2:

4.16.5 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:
i. SCC CTL RATIO
ii. SCC INBAND RATE
2. Set the desired SCC control ratio:
i. SCC CTL RATIO {1/1, 1/2, 1/3, 1/4, 1/5, 1/6, 1/7}
ii. This allows the user to simulate the framing used by the Satellite Control
3. Set the desired SCC in-band rate:
i. SCC INBAND RATE {300 to 115200}
ii. This allows the user to request the rate of in-band data for the overhead channel.
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:
i. ES INTERFACE {RS-232, RS-485}
ii. 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:
MN-OM20– Revision 5
User Data Rate: 1,024,000 bps
In-Band Rate: 19,200 bps
Control Ratio: 1 to 7
Minimum In-Band = (1,024,000 * 7)/((7 + 1) * 250) = 3,584
Slot Bits = (1,024,000 * (7 * 10))/(19,200 * (7 + 1)) = 466
Actual Ratio = (466 + 10)/466 = 1.021
User Data Rate: 6,312,000 bps
In-Band Rate: 19,200 bps
Control Ratio: 1 to 7
Channel Option (Pass-Thru Mode only). The SCC CTL RATIO is the ratio of
overhead in-band data to synchronizing words.
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).
OM20 Theory of Operation
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