S Registers 39
S27 Bit-mapped. V.25ter not enabled. Storable.
Bit 3,1,0. Communication mode (&Q, \N CMD)
■ 0 = Normal asynchronous
■ 1 = Sync mode 1
■ 2 = Sync mode 2
■ 3 = Sync mode 3
■ 4 = Direct
■ 5 = MNP
■ 6 = MNP/V.42
■ 7 = V.42
■ V.25ter enabled
Bit 3. Not used
■ Bits 1-0. Communication mode (&Q, \N command). 1 = Lease line
■ 00 use S36 communication mode setting
■ 01 synchronous mode 1
■ 10 synchronous mode 2
■ 11 synchronous mode 3
Bit 2. Leased line (&L CMD)
■ 0 =GSTN
Bit 5,4. Synchronous transmit clock source (&X CMD)
■ 0 = Internal
■ 1 = External
■ 2 = Derive from receiver (slave)
Bit 6. Bell / CCITT (B CMD)
■ 0 = CCITT
■ 1 = Bell
Bit 7. Reserved
S28 Bit-mapped. Storable.
Bit 1,0. Error Correction Maximum Block Size (\A CMD)
■ 0 = 64 bytes
■ 2 = 192 bytes
■ 1 = 128 bytes
■ 3 = 256 bytes
Bit 6,5,4,3,2. V.42 detection period (T400) in 50 milliseconds increments (%G CMD)
■ 0 = Infinite
■ 1 to 155 = number times.05 second
Default = 16 for.8 seconds
Bit 7. ODP/ADP (&A CMD)
■ 0 = Do not use ODP/ADP when initiating a reliable V.42 handshake
■ 1 = Use ODP/ADP when initiating a reliable V.42 handshake
