Mitsubishi Electric QS001CPU User Manual page 30

1
OVERVIEW
(4) Enhanced RAS
1
- 5 1.1 Features
(a) Enhanced memory diagnostics
The memory diagnostics equipped with the CPU module are enhanced.
(b) Redundant CPU
The CPU module has two CPUs (CPU A and CPU B). The operation results of
CPU A/CPU B are compared, and output only when the results are matched so
that incorrect outputs can be prevented. (When the compared results are
mismatched, the system stops.)
(c) Enhanced hardware diagnostics by hardware circuit
The diagnostic functions of the Table1.3 prevents incorrect outputs when a
hardware error which cannot be detected by the OS occurs.
Table1.3 Hardware diagnostics function added to the QS series CPU module
Diagnostics
Overvoltage/
undervoltage detection
Clock stop detection
CPU module
CPU
A
Operation
Compare
result
Figure 1.2 Redundant CPU
Overvoltage or undervoltage is detected for the power supply voltage
provided from the power supply module to the CPU module.
The input clock stop to the CPU module internal circuit is detected.
CPU
B
Operation
result
Output when matched
Diagnosis Contents