Radyne OM20, Инструкция по установке и эксплуатации

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OM20 Universal Outdoor Modem OM20 Theory of Operation
MN-OM20– Revision 5 4–25
Example 1:
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
(less
than In-Band Rate)
Slot Bits = (1,024,000 * (7 * 10))/(19,200 * (7 + 1)) = 466
Actual Ratio = (466 + 10)/466 = 1.021
Example 2:
User Data Rate: 6,312,000 bps
In-Band Rate: 19,200 bps
Control Ratio: 1 to 7
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
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:
i. SCC INBAND RATE {300 to 115200}
ii. 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:
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: