Comtech EF Data CDM-840 - Manual (Page 105)

CDM-840 Remote Router Revision 2
Ethernet-based Remote Product Management MN-CDM840
6–37
o VersaFEC MODCOD 4 – QPSK 0.803 o VersaFEC MODCOD 10 – 16-QAM 0.829
o VersaFEC MODCOD 5 – 8-QAM 0.642 o VersaFEC MODCOD 11 – 16-QAM 0.853
• Target Es/No Margin (0.0 to 4.5) – Use the drop-down list to select a margin value, in 0.5 dB
increments.
The ACM system is designed to switch based on thresholds that correspond
to a BER of 5 x 10 -8 for each MODCOD. However, in order to prevent oscillation
around two MODCODs at this exact value, 0.3 dB of hysteresis has been added.
Click [Submit] to save.
Tx ACM Status (read-only)
From left to right:
Column Description
Seconds since last LQRM Amount of time (in seconds) since an LQ RM (Link Quality Report Message)
message was received from the associated CDD-880 Multi Receiver Router.
Max Seconds since last LQRM Maximum amount of time since the last LQRM message was received.
IP Source of last LQRM The source IP Address from where the last LQRM message was received.
Last Reported Es/No EsNo value received in the last LQRM message.
Current MODCOD Currently selected MODCOD.
Current DataRate Current data rate based on current symbol rate and MODCOD.
Tx ACM Events (read-only)
In addition to the date- and time-stamp assigned for each event, information is presented in this
section as follows (from left to right):
Column Description
Reported ES/No EsNo value.
New MODCOD Newly selected MODCOD.
New Tx DataRate New data rate based on new MODCOD and current symbol rate.
Click [Clear ACM Events] to clear all ACM statistics from the buffer.