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Comtech EF Data CDM-750 User Manual

Page 199

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CDM-750 Advanced High-Speed Trunking Modem

Revision 2

Serial-based Remote Product Management

MN-CDM750

7–19

Parameter

Type

Command

(Instruction

& Qualifier)

Number of

Arguments

Description of Arguments

Response to

Command

Query

(Instruction &

Qualifier)

Response to Query

External

Frequency
Reference

EFR=

1 byte, value

of 0 thru 5

Command or Query.

Set or return the External Frequency Reference in the form x, where:
0 = Internal 10MHz (default)
1 = External 1 MHz

2 = External 2 MHz
3 = External 5 MHz

4 = External 10 MHz
5 = Internal 10MHz plus output (this means that the Reference is available on the “Ext Ref” rear connector (small

rear-panel LED indicates when ON).

Example: EFR=1 (selects External 1MHz)

EFR=

EFR?
EFR*
EFR#

EFR?

EFR=x

(see Description of
Arguments)

Adjustment for
the Internal
10MHz High-

stability
Reference

ADJ=

4 bytes,
numeric

Command or Query.
Set or return fine adjustment of the Internal 10MHz Reference on the High-Stability Frequency Reference module
in the form sddd, where:

s = sign (+ or –)
ddd = value, 0-999.

ADJ=
ADJ?
ADJ*

ADJ#

ADJ?

ADJ=sddd
(see Description of
Arguments)

Unit Test

Mode

TST=

1 byte, value

of 0 thru 8

Command or Query.

Set or return Unit Test Mode in the form x, where:
0 = Normal Mode (no test)

1 = Tx CW
2 = Dual Side Band (Tx Alternating 1,0 Pattern)
3 = Single Side Band

4 = IQ PN Sequence
5 = RF Loopback (auto configures Rx to match Tx)

6 = IF Loopback
7 = Digital Loopback

8 = I/O Loopback

Example: TST=5 (RF Loopback)

TST=

TST?
TST*

TST#

TST?

TST=x

(see Description of
Arguments)