I executed this command

DBCC CHECKDB('AlarmSwitch') WITH NO_INFOMSGS

It took about 3 minutes and then I got message 'Command(s) completed successfully.'

Its mean there is no problem with my DB. Am I right?

You are right we should not rely on these values. In fact we should store this kind of info in our own tables but because this db access layer was desinged by an other team for us about five years ago (for SQL Server 200) and they used this approach.