Comtech EF Data CDM-625A - Manual (Page 165)

CDM-625A Advanced Satellite Modem MN-CDM625A
Front Panel Operation Revision 3
6–39
6.2.1.7 CONFIG: ACM (Adaptive Coding and Modulation) (IP-ACM or
V2-ACM Modes Only)
Appendix M. ADAPTIVE CODING AND MODULATION (ACM)
ACM Config: Min/Max-ModCod Unlock-Action
Target-SNR-Margin ()
Use the ◄ ► arrow keys to select a parameter. Press ENTER.
6.2.1.7.1 CONFIG: ACM  Min/Max-ModCod
Min Modcod: 00 (B 0.488 0.488 bps/Hz)
Max Modcod: 00 (B 0.488 0.488 bps/Hz)
Use the ◄ ► arrow keys to select the top line to set your Min(imum), or bottom line for your
Max(imum), ModCod settings. For either setting, depending on your active ACM mode, use the
▲▼ arrow keys to define the range of ModCods over which the system will operate:
If using IP-ACM Mode:
• ModCod 00 is BPSK Rate 0.488 (0.49 bps/Hz);
• ModCod 11 is 16-QAM Rate 0.853 (3.41bps/Hz).
If using V2-ACM Mode:
• The minimum setting for VF2S (Short Block VersaFEC-2) and VF2L (Long Block VersaFEC-2) is
fixed at ModCod 00 (BPSK Rate 0.489 (0.49 bps/Hz)).
• For VF2S, the maximum selectable ModCod 35 is 32-ARY Rate 0.831 (4.153 bps/Hz).
• For VF2L, the maximum selectable ModCod 37 is 32-ARY Rate 0.879 (4.397 bps/Hz).
Press ENTER.
If you wish to constrain the system to run at a fixed ModCod, set the Min and
Max ModCod values to be equal.
The value of Max ModCod may be limited by other FAST codes installed. For
example, suppose the 4100 ksps FAST option is installed, and the symbol rate set
to 4100 ksps, the theoretical maximum data rate would be 14 Mbps at ModCod
11. However, if CnC is being used, with a 10 Mbps FAST limit the ACM Max
ModCod will be limited to ModCod 7, or 9.6 Mbps.