Comtech EF Data SDM-2020, Инструкция по установке и эксплуатации

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Operation SDM-2020 Satellite Demodulator
3–16 Rev. 3
INTF LOOPBACK Programs the modem for interface loopback operation.
Note: Available in ASI, ASI/LVDS, G.703, or SMPTE 310M interface.
On entry, the current status of interface loopback is displayed. Press [
↑
] or
[
↓
] to make the selection. Press [ENTER] to execute the change.
EXT-REF FREQUENCY Programs the external reference clock in multiples of 8 Hz,
On entry, the current setting for the EXT-REF frequency is displayed. Press
[
↑
] or [
↓
] to increase or decrease the frequency. Press [ENTER] to execute
the change.
TX TERRESTRIAL
CLOCK FREQUENCY Displays the current TX Terrestrial Clock frequency, as follows:
•
1544 kbit/s (available with T1/E1 compat intf)
•
2048 kbit/s (available with T1/E1 compat intf)
•
6312 kbit/s
•
8448 kbit/s
•
32064 kbit/s
•
34368 kbit/s
•
44736 kbit/s
•
51840 kbit/s
On entry, the current frequency for the TX Terrestrial Clock is displayed.
Press [
↑
] or [
↓
] to increase or decrease the frequency. Press [ENTER] to
execute the change.
TX CODING FORMAT Programs the transmitter for AMI, B8ZS, HDB3, and B3ZS coding.
On entry, the current format for the TX CODING is displayed. Press [
↑
] or
[
↓
] to change the format. Press [ENTER] to execute the change.
BUFFER CLOCK Programs the interface buffer output clock to one of the following modes:
•
RX (Satellite) – Sets the output buffer clock to the satellite
clock.
•
TX (Terrestrial) – Sets the buffer output clock to recover
timing from the incoming TX data clock.
•
INTERNAL – Sets the buffer clock to operate from the modem
internal clock. This also is a fallback clock.
•
EXT. CLOCK – Sets this clock source to the external clock.
On entry, the current Buffer Clock mode is displayed. Press [
↑
] or [
↓
] to
change the format. Press [ENTER] to execute the change.
RX CODING Programs the receiver for AMI, B8ZS, HDB3, and B3ZS coding.
On entry, the current format for the RX CODING is displayed. Press [
↑
] or
[
↓
] to change the format. Press [ENTER] to execute the change.
BUFFER SIZE Sets the size of the buffer.
On entry, the current buffer length is displayed. Press [
↑
] or [
↓
] to select
the desired buffer size. If selecting milliseconds, choose from 2 to 32
milliseconds, in increments of 2 milliseconds or 0 (Bypass).
BUFFER CENTER This configuration function is used to center the buffer. Choosing YES
centers the buffer.
On entry, the current position of the buffer is displayed. Press [
↑
] or [
↓
] to
change the format. Press [ENTER] to execute the change.