YOKOGAWA F3LC11-1F, User Manual

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A3-13
IM 34M6H41-02E 2nd Edition : Aug. 1, 2005-00
A3.3 Security Function
When an external modem is connected to this module, the FA-M3 connected to a public
line can be accessed from any higher-level computer.
This function uses a password (a 4-digit number) to restrict access and guard against
external intrusion.
Table A3.5 List of Registers Related to the Security Function
Data
Position
Number
Name Setting Range
Default
Value
36 #1
86 #2
Security Password
$0000-$9999
(BCD 4 digits)
$0000
F3LC12-1F: #1: for port 1/#2: for port 2
F3LC11-1F: use only #1. #2 is reserved.
Use the data position numbers given in the table when accessing the module from a ladder program. When accessing from
a BASIC program, use the data position numbers given in Tables A1.4 and A1.5 instead.
l
Operation of Security Function
This function is used on public lines.
The security function can be enabled by turning on DIP switch SW2-8 or by using the
software setting function. You must also preset the Security Password data position
number 36/86.
1. When a higher-level computer dials the PC link module and line connection is
successful, this module turns on input relay X09 (Connected from External) and
requests the higher-level computer for the password.
CONNECT 2400
←
The higher-level computer returns this string
when connected to a line.
This character string varies with the modem model and
setting.
PASSWORD
←
This module requests for a password.
2 The higher-level computer transmits the password pre-set in the module (a 4-digit
number).
You must attach a CR+LF in front of and behind the password. Transmit the
password within 60 seconds of receiving the “PASSWORD” string.
CR+LF+”1234”+CR+LF ← If the password is 1234.
3. If the preset password and the password transmitted from the higher-level computer
match, connection completes.
If the passwords do not match or input is not completed within 60 seconds, the line
is disconnected.
OK
←
If the password is correct, returns an “OK” string.
+++
← Returns this string if the line connected to this module is disconnected.
NO CARRIER