Z02205 datasheet(13/30 Pages) ZILOG

13 / 30 page

Z02205

ZiLOG

Modem Controller

PS001000-MOD0599

Table 2. AT Command Set

Command

Function and Description

Answer

The A command causes the modem go off-hook and respond to an incoming call. Uses

this command after the modem has returned the RING result code.

When modems successfully complete the answering process, they each return a

CONNECT result code and enter the On-Line state.

If no transmit carrier signal is received from the calling modem within the time specified

in S-register S7, the modem hangs up, returns the NO CARRIER result code, and enters

the Idle state.

Any commands following the answer command on the command line are ignored.

This command is aborted if a key is pressed before the answer process is completed, or

when DTR is off, if some options in the &Q or &D commands have been used.

Communication Standard

Option

The B command indicates to the modem which special telephone line modulation

standards to use. The modem can be configured to use:

Uses the ITU-T modulation standards for all telephone line data rates. This

includes V.22 for the 1200 bps telephone line data rate and V.21 for the 300

bps telephone line data rate. If S-register S37 is set to 1 (or 2), then V.23 is

used with the originating modem transmitting at 75 bps and receiving at

1200 bps. If S-register S37 is set to any other value, V.23 is not used.

If the 1200 bps telephone line data rate is required, Bell 212A is used

instead of V.22. This is the default value for North America. The 1200 bps

telephone line data rate is required only if:

•

S-register S37 is set to 5, or

• S-register S37 is set to 0, and the terminal data rate is 1200 bps.

If the 300 bps telephone line data rate is required, Bell 103 is used instead

of V.21. The 300 bps telephone line data rate is required only if:

•

S-register S37 is set to 3, or

•

S-register S37 is set to 0 and the terminal data rate is 300 bps.

If neither the 1200 bps nor 300 bps telephone line data rate are required,

then a setting of B1 is ignored and the modem responds as if B0 was set.

Same as B0 for the 1200 bps and 300 bps telephone line date rate. Uses

V.23 with the originating modem transmitting at 1200 bps and receiving at

75 bps, if S-register S37 is set to 1 or 2.

Same as B0 for the 1200 bps and 300 bps telephone line date rate. Uses

V.23 with the originating modem transmitting at 75 bps and receiving at

1200 bps, if S-register S37 is set to 1 or 2.

Data Carrier Detect

Options

&C determines how the modem’s DCD signal relates to the carrier signal from the other

modem. This option occurs only at the beginning of a telephone line connection. If &C is

issued from the Command state, it will not have an immediate effect.

&C0

During asynchronous operation (&Q0 in effect), DCD is on at all times.

During synchronous operation (&Q1), DCD indicates the state of the

carrier signal from the other modem using S-registers S9 and S10. This is

the default value in North America.

&C1

Indicates the state of the carrier signal from the other modem using S-

registers S9 and S10.

Z02205 Datasheet(PDF) 13 Page - Zilog, Inc.

Z02205 Datasheet(HTML) 13 Page - Zilog, Inc.

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Datasheet Download

Link URL