Comtech EF Data RCS10 - Manual (Page 64)

RCS10 Redundant Communication System Operation
TM058 - Rev. 2.3 Page 3-17
Each Modem and I/O card in an RCS10 slot operates in sync. Each slot in the RCS-10 system
consists of a DMD-10 modem and an IO card. The modem parameters are stored in non-volatile
memory allowing the modem to return to its previous settings and configuration upon reset, power
up, or hot insert. The I/O card parameters, on the other hand, are stored in the switch CPU card and
are associated with the particular slot the I/O card is plugged into. This allows the newly inserted
I/O card to match the operation of the modem already present in that particular slot. For instance, if
an I/O card is moved from slot 2 to slot 4, it will get re-programmed with the saved parameters of
slot 4. It is necessary for the user to make sure that the I/O card is programmed with the desired
parameters. Reprogramming the overhead and the interface types is recommended and might be
necessary.
Due to the nature of the RCS10 system whereas the DMD10 modems are completely independent
of the interface cards, the channel’s overhead parameters, both Mod and Demod, must be entered
or reentered on initial setup of a channel. This is also true if a DMD10 modem is moved from one
channel to another or if an interface card is moved from one channel to another. This can be done
by either reentering the framing (96 Kb for IDR, 16/15 for IBS) or by reentering the mode setting (IDR
or IBS) under both the Mod config. and Demod config.
When a prime is backed up, the backup modem uses the prime’s I/O card to carry traffic. At times,
the prime is placed in Service Mode, modified and reinserted into the RCS10 chassis. The user
must not make any modifications to the interface card as it may cause interruptions in traffic. Some
modem parameters such as Overhead, ESC Source and External EXC Source are relayed to the
I/O card as well.
3.4.4 Modem/I/O/Switch Communications
The RCS10 Switch M&C periodically queries the Modems and I/O card for current configuration and
status. upon power-up or hot insert, the I/O cards are initialized according to the parameters
associated with the slot. In case of failure, the Switch M&C logs a descriptive event in the event log,
sets a Minor Alarm, and asserts the appropriate faults. It will then periodically attempt to initialize
the failed I/O card.
The Modem parameters on the other hand are saved in the Modem’s non-volatile memory allowing
the modem to return to its previous settings. The Switch periodically queries the modem for updates
to its configuration. When a communication failure occurs, the Switch M&C takes the appropriate
actions, but there are side-effects; the front panel updates seem sluggish and commands to the
other Modems and I/O cards take longer to execute. The communication problems should be
resolved for proper operation to resume. The ‘MODEM CHANNEL CONNECTION TEST,’ Alarm
Status and Event Log should be used to help determine where the communication failure is
occurring.
3.4.5 Configuration Copy
The Configuration Copy is a feature that enables a user to store/retrieve up to five modem and
interface card configurations in non-volatile memory. These are in addition to the current running
configuration.
The interface card configurations are tagged to the slot, and are stored in the switch. The modems,
on the other hand hold their own settings. The user can copy from and copy to any configuration in
memory including the current running configuration. Source and destination configurations must be
different.
When instructed to copy a configuration, the switch sends a command to the modem to copy the
configuration, and if successful, the switch updates the slot configurations as well. If the
destination configuration is the current configuration, the modem re-initializes itself and uses the
new settings. The switch interface card is only updated when the destination configuration is the
current configuration.
A user must be careful not to copy onto the current configuration unless that is desired, or