Comtech EF Data CDM-750 - Manual (Page 176)

CDM-750 Advanced High-Speed Trunking Modem Revision 2
Ethernet-based Remote Product Management MN-CDM750
6–32
• Tx ModCod and Remote Es/No (ModCod / Rem Es/No) – This graph is particularly
useful when the modem is running is ACM mode as it maps the remote Es/No of the far
end modem synchronously along with the near side (local) Tx ModCod used. Note that
two pieces of data are graphed in time synchronous manner:
o The left side of the graph has a vertical key of Tx ModCod (blue).
o
The right side of the graph has a vertical key of Remote Es/No (red).
In this format, the graph depicts changes in ModCod that occur when the reported
Remote Es/No meets the Es/No trigger points to switch up or down.
Note that the Remote Es/No is the “reported” Es/No of the far end modem as seen by
the local modem. This reported Remote Es/No data can be 250ms to 400ms old as this is
the amount of time it can take for this data to traverse the satellite link for processing
by the local modem.
When more than one ModCod is used in the smallest interval period allowable by the
graph, the most common ModCod used in that time interval is displayed.
• Tx Capacity Configuration Parameters – This is a graphical representation of some of
the common configuration settings that can affect user data rate, and typically do not
change:
o Pilots On or Off
o Normal Block or Short Block
o Symbol Rate
These parameters are shown to provide you with a more complete representation of user
capacity, when looked at in conjunction with the other graphs provided on these pages.