Chapter 482 The Damaged Distribution Box (Please Vote and Subscribe!!!)

"Distribution box?"

The old principal was stunned for a moment, raised his hand and pointed outside the gymnasium:

"As for the distribution box"

"We will install it on the outer wall."

Without saying anything, Sakaki Makoto immediately walked out the door.

Leaving a few people to guard the scene, Megure Jusan and others hurried to follow.

They were very curious about what Sakaki Makoto wanted to do.

Is this case related to the distribution box?

The group hurried to the outer wall of the gymnasium, and under the leadership of the old principal, they found a metal box hanging on the wall.

At this moment, the box that should have been locked was opened violently.

The iron lock fell to the ground, and the gap on it was smooth and neat, as if it had been twisted off by something like scissors.

"This"

Megure Jusan was shocked:

"Who did this?"

"The criminal."

Holding a cigarette in his mouth, Sakaki Makoto said expressionlessly:

"I just found out that the smoke alarm used in the gymnasium is a wired network type, right, Mr. Uematsu?"

"Yes."

The old principal nodded:

"That's right."

"Brother Sakaki Makoto, what does this have to do with the case?"

Confused, Megure Jusan didn't understand why Sakaki Makoto suddenly focused on the alarm.

"It's a big deal"

With a sigh, Sakaki Makoto opened the cover of the distribution box and saw that several lines inside had been completely disconnected.

As expected

Rubbing his eyebrows, Makoto Sakaki explained:

"The smoke alarm used by Teitan Elementary School is very advanced. It adopts the NITTAN-CCA-ASW remote networking system. Once a fire occurs, it can trigger functions such as sprinkler and buzzer while alarming."

"But"

"The school uses ADSL network."

"What the hell?"

Everyone was dumbfounded. They didn't understand what Makoto Sakaki was talking about. It was as obscure as reading a wordless book.

Megure Jusan opened his mouth and asked:

"Can you explain it in more detail?"

".Sure."

Sakaki Makoto reached out and picked up a broken line in the distribution box, saying:

"As a new technology, the ADSL network uses frequency division multiplexing technology to divide ordinary telephone lines into three relatively independent channels, such as telephone, upstream network, and downstream network, to avoid mutual interference."

"In other words, devices using ADSL technology can divide multiple lines, connect multiple devices, and finally transmit data through an ADSL terminal-'cat'."

"Ah"

Megure Jusan pondered for a while:

"So what?"

Fuck!

Sakaki Makoto was speechless.

He explained it so thoroughly, but Megure Jusan still didn't understand?

Can you use electronic devices? Oh.

Megure Jusan

seems to know nothing about electronic devices.

This is a long explanation.

Time waits for no one, and Sakura Makoto doesn't want to waste so much words, so he can only simplify the language:

"When a fire occurs, the smoke alarm in the gymnasium sends a signal, and the signal will pass through the telephone line in my hand, first into the ADSL terminal in the school, and then pass it to the fire department, telling them that a fire has occurred somewhere."

"At this time, the fire department will call the school to ask if there is a fire, and then decide whether to send an alarm."

"It's like a local area network. Once the telephone line outside the gymnasium is cut off, it will be completely isolated. Even if the smoke alarm can work normally, the signal cannot be transmitted!"

Scratching his head, Megure Jusan laughed dryly twice, a little embarrassed.

Seeing him like this, Sakura Makoto immediately understood that he didn't understand at all.

However,

Sato Miwako understood:

"I see. But why not just pass the signal to the fire department? It would be redundant?"

"Because the line length exceeds 1.5km, the fire department uses an ADSL telephone line real-time monitoring feedback system."

Inspector Yuminaga took two steps forward and looked at Makoto Sakaki with appreciation:

"Mr. Makoto Sakaki, have you worked in the fire department before?"

"No."

"Then how do you know this knowledge?"

"Isn't this common sense?"

Spreading his hands, Makoto Sakaki was also helpless!

Ordinary people may not need to know so much, but as a policeman

If you don't even know this little knowledge, how can you deal with difficult criminals?

You know, criminals are also constantly learning and improving!

There are more and more high-IQ crimes. If you can't keep up with the opponent's rhythm, you can only be pressed to the ground.

If you want to be the first to come after you, there is a necessary prerequisite-fast!

That's right, as long as you act faster and react faster than your opponent, you can complete a series of complex operations such as grabbing a knife with bare hands and dodging bullets.

The eyes must be sharp, and the hands must be steady, accurate, and fast!

This is the secret of Makoto Sakaki's dodging bullets, and it is also the secret of his success in solving cases.

"Even if the criminal cut off the telephone line, the water-sprinkling buzzer system was not triggered!"

Megure Jusan said blankly:

"What is the purpose of the criminal doing this?"

"As I said just now, the smoke alarm will transmit a signal to the terminal."

Makoto Sakaki said lightly:

"In places like schools with multiple buildings, the lines are usually connected to the fire alarm controller for unified processing and planning."

"The CCA-ASW smoke alarm system used by Teitan Elementary School is an intelligent temperature-sensing detector that can monitor indoor temperature in real time, transmit the data collected by itself to the LAN host, receive the information sent back by the host, and independently judge whether it is necessary to turn on the sprinkler buzzer and report the fire."

"I know!"

After hearing so much, Megure Jusan finally got some clues:

"This CCA alarm system also relies on telephone lines!"

"If the criminal cuts off the telephone line, it will be useless!"

"."

The words are rough but the truth is not rough, Megure Jusan is right.

It is not difficult to guess the purpose of the criminal deliberately cutting off the telephone line. There are roughly two directions:

1. The other party wants to use a fire to destroy all evidence.

2. Burning down the gymnasium is one of the criminal's purposes.

In Makoto Sakaki's opinion.

The former and the latter are possible.

The criminal set up the crime scene in the gymnasium, and there must be something inside.

But.

The criminal deliberately chose a time when no one was around to act, which shows that the other party did not want to hurt innocent people, or wanted to escape calmly.

After all, it takes time for the fire to spread, far more than one or two minutes.

The cut telephone line provided Makoto Sakaki with a different way of solving the case.

What tool did the criminal use to twist the iron lock?

Were the fingerprints on the tool wiped off?

Where could the criminal who had never left the campus hide the tool?

All kinds of mysteries will become key information to solve the case.

After telling his idea to Megure Jusan, Megure Jusan also sent people to conduct a carpet search on campus.

There are not many tools that can twist the iron lock, and the scope is narrowed down at once.

Conan and Hattori Heiji also joined the search army. Just when Makoto Sakaki was about to take a break and wait for the tool man... Ugh!

When the good brothers came back with clues.

The little girl standing quietly under the cypress tree not far away attracted his attention.