Toshiba T2N - Manual (Page 132)

5.RAS Functions
User’s manual 119
The meaning of RAS is Reliability, Availability and Serviceability, the RAS
function is the general term used for the functions installed in the T2N which
increase the reliability and serviceability of the applied systems and support the
operation of the system.
This section explains the self-diagnostic functions installed in the T2N, the
maintenance functions, the debugging functions and the system checks which
can be run by the T2N user.
The T2N runs checks on itself. The details of these self-diagnostics which are
designed to prevent abnormal operation, the timing of the diagnosis and procedure
when malfunctions are detected are shown below.
In building up the system, consider the system operation safety should a in
case of a T2N shut down (fail safe) and the system operation backup function.
In the following explanation, error registration means the storing of the details of
the error and the time when it occurred on the event history table; error down
means that all the outputs turn OFF and ERROR mode is entered; alarm means
that the erroris registered, the special relay is set, and running is continued.
(1) Diagnostics at system initialization (when power supply is turned on)
Diagnostics Diagnostics details Processing when error detected
System ROM BCC check BCC check on the correctness
of the system ROM Error registration takes place,
FLT LED flash. (Programmer
communication impossible)
System RAM check The system RAM read/write is
checked. Error registration takes place,
the FLT LED flashes.
(Programmer communication
impossible)
Peripheral LSI check Peripheral LSI checked for
normal initialization. (Read back
check) Error registration takes place,
the FLT LED flashes.
(Programmer communication
impossible)
LP check LP ( language processor) is
checked for normal initialization. Error registration takes place,
ERROR mode is entered. (Error
reset command invalid)
User program memory
check BCC check on the correctness
of the content of the user
program memory. (Checked
after initial load when peripheral
memory is present) Error registration takes place,
ERROR mode is entered.
User data memory check The user data memory
read/write is checked. Error registration takes place,
ERROR mode is entered. (Error
reset command invalid)
Peripheral memory check BCC check on initial loading of
the peripheral memory
(EEPROM). Error registration takes place,
ERROR mode is entered.
5.1
Overview
5.2
Diagnostics