Nera Inmarsat-c Service Manual page 34

4) Memory
EEPROM (8 kbyte) and SRAM (256 kbyte) are connected to CPU. SRAM is backed up by
C90 (2.2 F) super capacitance for 72 hours.
Table 2.3.1 lists the memory contents of RF CON/PU board.
Memory
SRAM
(U22, CY62136VLL)
EEPROM
(U15, CAT25C64AP)
Note) When replacing RF CON/CPU board,
remove the EEPROM(U15) old board and put it
on the new board.
Forward/Return ID
This is the secret ID used for the communication between MES and LES. Forward ID is
used from LES to MES, Return ID is used from MES to LES.
The sum of both ID is 2x3 bytes. Each ID is 6-figure HEX code.
DNID
After making a contract, the information provider sends the ID for data network (DNID) to
MES via LES.
The service such as data reporting is based on the DNID. When DNID is received from LES,
it is listed into "F5-3/Data Network ID" automatically. DNID information consists of 2
bytes.
ENID
To get the EGC broadcasting Fleet NET service, the contract is needed. The information
provider sends the ID for group call (ENID) to MES via LES.
When ENID is received from LES, it is listed into "F4-2/EGC Network ID List"
automatically.
DNID information consists of 2 bytes.
Table 2.3.1 Memory contents of RF CON/CPU board
Volume
256 kbyte [F7]-6:LES information
Forward/Return ID: 2x3 bytes
ENID, DNID: 64x2 bytes
64 kbyte
[F8]-1, [F8]-2, [F8]-5, [F8]-9-3, [F8]-9-4,
[F7]-5, [F7]-7-2 (See page 2-27)
2-14
2.3 Terminal unit, IC-215
Contents
Fig.2.3.11 Configuration of EEROM