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D.5.7 modem performance information – Comtech EF Data CDM-625 User Manual

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CDM-625 Advanced Satellite Modem

Revision 15

Appendix D

MN-CDM625

D–50

D.5.7

Modem Performance Information

Parameter

Type

Command

(Instruction

& Qualifier)

Number of

Arguments

Description of Arguments

Response to

Command

Query

(Instruction &

Qualifier)

Response to

Query

Rx Signal

Level

N/A

5 bytes

Query Only.

Unit returns the value of the Rx signal level, in dBm, between –20 and –90 dBm.

If >-20dBm, returns RSL=GT-20 (GT = ‘greater than’)

If <-90 dBm, returns RSL=LT-90 (LT = ‘less than’)

If in the range of –20 to –90dBm,

returns RSL=-xx.y (resolution 0.5dB)

Example: RSL=-45.5 (indicating –45.5 dBm)

N/A

RSL?

RSL=xxxxx

(See Description of

Arguments)

Rx Frequency

Offset

N/A

6 bytes

Exception –

600L

Emulation:

5 bytes

Query only.

Unit returns the value of the measured frequency offset of the carrier being demodulated.

Values range from ± 0 to ± 200 kHz, 100 Hz resolution.

Returns 999999 if the demodulator is unlocked.

The maximum Rx Frequency Offset corresponds to the Receive Sweep Width (RSW)
Example: RFO=+002.3 (selects + 2.3 kHz)

N/A

RFO?

RFO=sxxx.x

(See Description of

Arguments)

Buffer Fill

State

N/A

2 bytes

Query only.

Unit returns the value of the buffer fill state, between 1 and 99%. Returns 00 if demodulator is unlocked.
Example: BFS=33 (selects 33%)

N/A

BFS?

BFS=xx

(See Description of

Arguments)

Rx BER

N/A

5 bytes

Query only.

Units returns the value of the estimated corrected BER in the form a.bx10

-3

, where:

First three bytes are the value.

Last two bytes are the exponent.

Returns 99999 if the demodulator is unlocked or BER data is unavailable.
Example: BER=4.8E3 (selects BER=4.8 x 10

-3

)

N/A

BER?

BER=xxxxx

(See Description of

Arguments)

Rx Eb/No

N/A

4 bytes

Query only.

Unit returns the value of Eb/No, between 0 to 16 dB. Format xx.x, resolution 0.1 dB.

Returns 99.9 if demod is unlocked.

Returns +016 for values greater than 16.0 dB.
Example: EBN=12.3 (selects Eb/No = 12.3 dB)

N/A

EBN?

EBN=xxxx

(see Description of

Arguments)

Redundancy

State

N/A

1 byte, 0 or 1

Query only.

Unit returns the redundancy state of the unit in the form x, where:

0=Offline

1=Online
Example: RED=1 (selects Online)

N/A

RED?

RED=x

(See Description of

Arguments)

Temperature

N/A

3 bytes

Query only.

Unit returns the value of the internal temperature sensor (degrees C) in the form xxx, where:
Example: TMP=+26

N/A

TMP?

TMP=xxx

(see Description of

Arguments)