S109 - Carrier Speed Selector

Description
Register S109 selects the speeds available for V.32, V.32 bis, V.34, and V.FC carrier handshake, retrains, and rate re-negotiations. Register S37 selects the highest carrier speed that may be used during handshakes. If the N0 command is selected, the speed indicated by S37 and one of the speeds selected by S109 must match; the modem connects only at that speed. Register S37 and the N0 command do not affect the modem speed while in V.32bis mode during a retrain or rate re-negotiation procedure.

Note: While performing a V.32, V.32 bis, V.34, or V.FC handshake, the modem connects only at speeds enabled by S109.

If Ans-A or Orig-A handshake behavior is selected (defined for Nn command) and the speed indicated by S37 is one of the set covered by S109, then the speed must match one of the speeds selected by S109 or when the modem enters the handshake process the modem sets S86 to value 16, hang-up, and sends NO CARRIER result code. If the speed selected by S37 is not one of those covered by S109, then the handshake proceeds normally.

Type
bit-mapped; 4095 with V.34, 4094 without V.34

Stored by &Wn
yes

Displayed by &V
yes

Bit Map

Bit     Value         

0       2400 bits/s   

1       4800          

2       7200          

3       9600          

4       12000         

5       14400         

6       16800         

7       19200         

8       21600         

9       24000         

10      26400         

11      28800         

12      31200         

13      33600         

14      reserved      

15      reserved

Note: The decimal values may be added to specify several speeds from which the modem can choose. For example, the factory default is 4094 which is the sum of decimal values (2+4+8+16+32+64+128+256+512+1024+2048=4096).

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