Comtech EF Data CDM-600/600L - Manual (Page 160)

CDM-600/600L Open Network Satellite Modem Revision 3
Clocking Modes and Drop and Insert (D&I) MN/CDM600L.IOM
8–6
8.5 Drop and Insert (D&I) with ESC and AUPC
The Drop and Insert (D&I) framing has been extended with the release of Firmware Version 1.4.0
for the CDM-600L and Firmware Version 2.1.0 for the CDM-600 to include the capability of
adding high-rate ESC (Engineering Service Channel) and AUPC (Automatic Uplink Power
Control). Currently this is available for E1 operation only. Refer to the pertinent manual section for
details of each of these features.
The high-rate ESC channel operates the same for D&I as it does for IBS framing, using bytes 16
and 48 of the overhead channel, as well as half of byte 32, to pass the data characters over the
satellite link. Because these bits are reserved for signaling, this new feature is not available for
E1-CAS mode. The AUPC portion (which is not available with IBS framing) occupies the unused
first bit of the unique word (byte 0).
Prior to firmware version releases mentioned above, neither ESC nor AUPC could be combined
with D&I. To enable Drop and Insert with ESC and AUPC, the correct sequence of
configuration must be followed – this applies when configuring via the front panel, or when
using individual remote control commands.
From the modem front panel:
D&I WITH ESC AND AUPC – CONFIGURATION SEQUENCE
Step Front Panel Operation Parameter Setting
Chapter 5
Sect. Ref.
1 CONFIG: MODE
D&I
(Requires D&I FAST option)
5.4.2
2 CONFIG: D&I E1-CCS 5.4.6
3 CONFIG: MISC Æ HIGH-RATE-ESC On 5.4.9.4
4 CONFIG: TX Æ POWER Æ MODE AUPC 5.4.3.2
The available ESC baud rates for D&I depend on Tx and Rx datarate. They are the same as those
for high-rate IBS ESC. Pinout information for the P3A Overhead Interface Connector which
carries the ESC channel is shown in Sect. 3.3.1.
The maximum ESC baud rate is limited by the lower of the Tx or Rx data rates. If a data rate is
edited so that a baud rate is no longer available, the baud rate will automatically be reduced to the
next permitted value. The data-rate breakpoints are as follows:
Data rate Max ESC baud rate
64 kbps 2400
≥128 kbps 4800
≥256 kbps 9600
≥384 kbps 14400
≥512 kbps 19200
≥768 kbps 28800
≥1280 kbps 38400 (Note: breakpoint change)
Note: For AUPC to be effective, it must be enabled on both the local & remote modems.