Basic to TBASIC Reference
Manual| SETPASSWORD string |
| Purpose | When this statement is executed, the PLC will not properly
respond to any host link commands sent to it except the command "PWxxxx...xx"
which must contains the same string "PWxxxx...xx" (not more than 19 characters)
as defined in the SETPASSWORD command. All other commands will receive a "PWER"
response indicating a "password error" state. Once the correct password has been
accepted the PLC will work as normal and respond to all host link commands. Execution of
"PW" host link command without any string will put the password lock back in
force to prevent unauthorized access When using i-TRiLOGI the editor will automatically
prompt you to enter the password string if it encounters a PLC which has been
password-locked. Note that the password is case sensitive. |
| Examples | SETPASSWORD "I love i-TRiLOGI" |
| Comments: | This feature is mainly used to protect an unattended PLC
which is linked to an auto-answer modem. Without password protection anybody can dial in
with a TL41.EXE and have full control of the PLC, which may be a serious security problem.
When TL41.EXE disconnects the modem it automatically executes the "PW" command
to re-arm the password lock so that there will not be unauthorized access by subsequent
callers. Within the PLC software you may also use a timer to periodically re-arm the PLC
with this command for maximum protection. You can also use different passwords for
different time of the day or a set of rotating passwords to provide greater security. If you are linking the PLC to the internest via i-TRiLOGI , you will notice that the TLServer already provides username/password authentication. However, the password here works independent of the access provided via TLServer, hence this command can still be used to provide an additional layer of security against unauthorized access to the PLC. |
Basic to TBASIC Reference
Manual