3Com 56K Command Reference Manual page 189

Register Default Function
Bit
S53 126 Bit-mapped register. (See Chapter 1, Using the AT
Command Set, for instructions about how to set
bit-mapped registers.)
0
1
2
S54 64 Symbol rate bit-mapped register used primarily by 3Com
Technical Support for debugging purposes.
Bit
0
1
2
3
4
5
6
7
S55 0 Trellis code bit-mapped register used primarily by 3Com
Technical Support for debugging purposes.
Bit
0
1
2
3
4
5
6
7
Value Result
1 Enable dial security.
2 Enable autopass fallback.
4 Enale local-access password
protection.
Enabling local-access password
protection disables the &Zn=s
command (which stores up to 10
phone numbers) because stored
phone numbers occupy the same
space in NVRAM as the dialback
numbers for Dial Security accounts.
Value Result
1 Disable 2400 symbol rate.
2 Disable 2743 symbol rate.
4 Disable 2800 symbol rate.
8 Disable 3000 symbol rate.
16 Disable 3200 symbol rate.
32 Disable 3429 symbol rate.
64 Disable V.8 Call Indicate (CI).
128 Disable V.8 Mode.
Value Result
1 Disable 8S-2D mapping.
2 Disable 16S-4D mapping.
4 Disable 32S-2D mapping.
8 Disable 64S-4D mapping.
16 Reserved.
32 Reserved.
64 Reserved.
128 Enable phase roll detection.
S-Registers I-7