PCKN-OIL738
17
5
Configuration
5.1 Internal configuration
(1) I/O and CPU circuits
Fig. 5.1 shows the internal block diagram of the model CBV2-A01D1.
Voltage input is converted into AC signals at the electronic circuit level via the auxiliary transformer
and filter circuits. These signals are retained as a form of DC signal in the sample hold circuit on each
channel sharing a same time. The multiplexer selects a channel to take the signal and sends it to an
A/D converter. The signals are converted to digital signals sequentially in the converter to be sent to
the CPU.
The setting circuit is used to input setting data into the CPU.
These inputs will be used to carry out the functions shown in Fig. 5.2 “Internal function block diagram”,
and then issue output signals to the display and output relay.
(2) Self-diagnosis
circuit
When the self-diagnosis function detects that the electronic and power circuits are normal, the output
relay will be energized to open the self-diagnosis output contact (break contact).
The self-diagnosis output contact (break contact) will be closed when a failure occurs in the circuits
above or when the built-in power fuse burns.
