Comtech EF Data CDM-750 - Manual (Page 100)

CDM-750 Advanced High-Speed Trunking Modem Revision 2
Front Panel Operation MN-CDM750
5–22
5.2.2.2.5 (CONFIG) Tx: Mod (Modulation)
Modcod=QPSK 1/2 ( v)
Use the ST arrow keys to select the modulation and FEC type, and then press ENTER. Note the
following:
• Use the ModCod setting “Auto (ACM)” when running in ACM mode. In ACM mode, you do
not directly control the ModCod used at any given moment, but rather the ModCod
chosen for the Tx carrier is based on the rules and configuration of the ACM parameters.
See Sect. 5.2.2.5 CONFIG: ACM for configuration of ACM parameters.
• The upper range of modulation and coding as well as Auto (ACM) capability is dictated by
the FAST option(s) installed.
5.2.2.2.6 (CONFIG) Tx: Data
Tx Data Rate Tx Symbol Rate
()
Use the W X arrow keys to select Tx Data Rate or Tx Symbol Rate, and then press ENTER.
(CONFIG) Tx: Data Æ Tx Data Rate
To configure the Tx Data Rate of the modem, the modem must be in Single Stream
Mode with only the Ethernet interfaces active. You can tell when the modem is in
Single Stream Mode / Ethernet only when the minimum data rate (MIN_DR) is zero
(000000.000) and the Read Only (RO) indication does not appear at the upper right‐
hand of the menu.
If the screen displays any minimum data rate other than zero, this indicates that
the modem is in MultiStream Mode – the data rate cannot be changed while in
MultiStream Mode. See Sect.5.2.2.1.1 Single Stream Mode vs. MultiStream Mode
Operation for instructions on entering into or exiting out of MultiStream Mode.
ETH_DR + MIN_DR = TOT_DR (RO)
019484.479__034883.520__054367.999Kbps
Referring to the example shown here: Per the
ETH_DR + MIN_DR = TOT_DR(RO) equation
provided on the top line, note the following:
Operand Means Description
ETH_DR Ethernet Data Rate This is all data associated with the Ethernet data interfaces. It is always
TOT_DR – MIN_DR