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Error control – ZyXEL Communications Omni 288S User Manual

Page 39

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Chapter 4 - Advanced Data Communications

4-5

Certain modes, such as the ZyXEL proprietary modes, Fax mode, and Cellular
modes can be added or omitted from the auto-negotiation process using the S-
registers settings listed below.

Mode

Disable

Enable

ZyXEL 19200

S43.1=1

S43.1=0 *

ZyXEL16800

S43.0=1

S43.0=0 *

G3 Fax

S38.4=1

S38.4=0 *

Cellular

S43.3=1 *

S43.3=0

* Denotes default setting.

Setting the DTE to DCE Rate

The Omni 288S DTE to DCE rate can be determined in three ways:

1. By default the DTE to DCE rate is equal to the DTE speed set by S20

(default S20=1 for 115200 bps). This mode is set with &B1.

2. To set the DTE to DCE rate to follow the connect speed, set &B0.

3. To force the modem to use a fixed baud rate when answering, set S18 to the

corresponding value.

S18=

Speed

S18=

Speed

0 *

Disable fixed rate

15

300 bps

1

115200 bps

16

307200 bps

2

76800 bps

17

153600 bps

3

57600 bps

18

102400 bps

4

38400 bps

20

61440 bps

5

19200 bps

21

51200 bps

6

16800 bps

22

624000 bps

7

14400 bps

24

124800 bps

8

12000 bps

25

62400 bps

9

9600 bps

26

41600 bps

10

7200 bps

27

31200 bps

11

4800 bps

28

24960 bps

12

2400 bps

29

20800 bps

13

1200 bps

32

230400 bps

14

460800 bps

46

921600 bps

* Denotes default setting

Error Control

Error control keeps the modem data link error-free by detecting and re-
transmitting erroneous data. ZyXEL modems support both MNP and V.42 error
control protocols. The MNP protocol was an industry de facto standard
developed and licensed by Microcom, Inc. ZyXEL modems support level 4 and 3