FP Modem-EU Technical Manual
3.7 DTMF Alarm and DTMF Telecontrol
3.7.2 Decoding DTMF Tones for Remote Control
When the FP Modem-EU decodes DTMF tones for remote controlling:
• The modem dials up a voice telephone (or vice versa).
• The human operator uses touch keys to send out DTMF tones.
• The modem decodes the DTMF tones and sends key codes to the PLC.
• The PLC performs programmed functions according to the key code.
Main settings
Command Description
ATR0 Default: DTMF decoder disabled
ATR1 DTMF decoder for remote control activated
# Entered by human operator (via telephone key pad) after dial-up (or call accepted)
to activate DTMF decoding at the FP Modem-EU (distant site)
DTMF:x Generated by the modem if a DTMF code x was received (see table below)
With the ATR1 command you can activate DTMF remote control. After dialing up or accepting
an incoming call, the modem waits for the start character (DTMF #) for 5 seconds after
occupying the telephone line. After the distant station or the human operator has sent the #
DTMF key code, the modem switches to DTMF receiving command mode. All DTMF characters
detected are passed on to the RS232C. The start character # is not transferred.
If no start character is detected within 5 seconds, the modem starts with the handshake, i.e. the
data connection sequence.
The decoded DTMF tones are sent to the controller in the form "DTMF:x<CR>" via the RS232C.
Where x stands for the decoded DTMF tone: 0...9,*,#. The x is replaced by ASCII code.
Code via RS232C Touch keys ASCII code
DTMF: 0
...
0
...
30 HEX
...
DTMF: 9
9 39 HEX
DTMF: *
* 2A HEX
DTMF: #
# 23 HEX
With this function a human operator can telecontrol a PLC system by using the buttons (touch
tones = DTMF codes) of his voice telephone.
Please use the FPWIN Pro Library "Modem" for FPWIN Pro programming
support.
41
To Next Page
Loading...
