參數(shù)資料
型號(hào)： MT8870
廠商： Mitel Networks Corporation
英文描述： ()
中文描述： （）
文件頁(yè)數(shù)： 18/23頁(yè)
文件大?。?/td> 177K
代理商： MT8870
MSAN-108
Application Note
A-62
A scheme for coding ASCII characters using one and
two digit DTMF signals is outlined in the appendix.
Notice that on a telephone keypad keys 2 through 9
are represented by three alpha-characters as well as
a numeral. To send an alpha-character, using this
scheme, first press the key on which the character
appears then press the key corresponding to the
position in which the character appears on its key (1,
2 or 3 ). Numerals are sent by touching the desired
number followed by a zero. The asterisk (*) and
octothorp (#) have been reserved for
"
space
"
and
"
return
"
respectively. A plastic overlay the size of a
credit card expands the number of useable
"
positions
"
on each button (Fig. 20). This serves as a
guide for sending other ASCII codes and fits snug
into a credit card wallet. ASCII control characters
that are not commonly used could be listed at the
bottom of the card. This user-friendly algorithm
eliminates the need to memorize conversion codes
and allows significant functionality even without the
overlay reference.
A simple block diagram shows how this scheme may
be implemented for a home DTMF control system
(Fig. 21). A ringing voltage detector signals the
microprocessor
of
an
microprocessor, after the prescribed number of
rings, closes the answer relay engaging the proper
terminating impedance. A two-to-four wire converter
splits
bidirectional
audio
telephone line into separate single ended transmit
and receive paths.
incoming
call.
The
from
the
balanced
Receive audio is then switched to the DTMF receiver
through the crosspoint switch. Upon receiving a
valid DTMF signal, the microprocessor is alerted by
Figure 21 - Block Diagram of Home DTMF Remote Control System
FROM PHONE
EXCHANGE
ANSWER
RELAY
LINE TERMINATION
2/4 WIRE CONVERTER
AUDIO
IN
OUT
OPTIONAL
FM TRANSMITTER
120V
MAINS
RING
DETECTOR
PASSWORD
THUMBWHEELS
OPTIONAL
MICROCOMPUTER
MT8804
CROSS-
POINT
SWITCH
HANDSFREE
INTERCOM
STATION
MT8870
DTMF
RECEIVER
LOGIC OR
MICROPROCESSOR
CONTROL
SYSTEM
DATA
PORT
OUTPUT
DRIVERS
REMOTE
FM/DTMF
RECEIVER
AND
CONTROL
OUTPUT
DRIVERS
TO REMOTE
CONTROLLED
DEVICES
TO NEARBY
CONTROLLED
DEVICES
An FM transmitter could be used to couple control signals for distribution over existing power lines. This
would eliminate the need for installing wires between the DTMF control unit and remote controlled
devices.
相關(guān)PDF資料
PDF描述
MT8880C ISO2-CMOS Integrated DTMFTransceiver
MT8880CE-1 ISO2-CMOS Integrated DTMFTransceiver
MT8880CC ISO2-CMOS Integrated DTMFTransceiver
MT8880CE ISO2-CMOS Integrated DTMFTransceiver
MT8880CN ISO2-CMOS Integrated DTMFTransceiver
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MT8870BE 制造商:Panasonic Industrial Company 功能描述:RECEIVER
MT8870D 制造商:MITEL 制造商全稱:Mitel Networks Corporation 功能描述:ISO2-CMOS Integrated DTMF Receiver
MT8870DC 制造商:MITEL 制造商全稱:Mitel Networks Corporation 功能描述:ISO2-CMOS Integrated DTMF Receiver
MT8870DC-1 制造商:MITEL 制造商全稱:Mitel Networks Corporation 功能描述:ISO2-CMOS Integrated DTMF Receiver
MT8870DE 制造商:Microsemi Corporation 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*