AN93

 

 

 

Table 40. Extended AT& Command Set (Continued)

 

 

 

Automatic determination of telephone line type.

 

Result code: WXYZn

 

W:

0

= line supports DTMF dialing.

 

 

1 = line is pulse dial only.

 

X:

0

= line supports 20 pps dialing.

&X1

 

1

= line supports 10 pps dialing only.

 

Y:

0

= extension network present (PBX).

 

 

1

= outside line (PSTN) connected directly.

 

Z:

0

= continuous dial tone.

 

 

1

= make-break dial tone.

 

n:

0–9 (number required for outside line if Y = 0).1

&X2

Same as &X1, but Y result (PBX) is not tested.

Y2A2

Produce a constant answer tone (ITU-T) and return to command mode. The answer tone continues

until the ATH command is received or the S7 timer expires.

 

&Z

Enter low-power wake-on-ring mode.

 

 

 

 

Notes:

1. The initial number attempted to test for an outside line is controlled by S51 (default = 1).

2. AT&$ reflects the last AT&P command issued but does not reflect any subsequent changes made by writing U registers with AT:U.

TIP +

600 Ω

Si3018 VTR

10 µF

RING

Figure 25. Phone Line Termination Circuit

IL

Rev. 1.3

79

Page 79
Image 79
Silicon Laboratories SI2494/39, SI2493/57/34/15/04 manual Tip +