Signal collection method and signal collection device

A signal collection device that collects internal states indicated by signals in an electronic circuit device including a bus, the signal collection device comprising:

• a fine resolution data storage that obtains and stores the internal states per a first period;
• a coarse resolution data storage that stores a first data transfer amount, which is a data amount transferred by the bus per a second period, which is longer than the first period;
• a pattern generator that stores the second data transfer amount calculated in advance;
• and
• a determiner that obtains the first data transfer amount from the coarse resolution data storage, obtains the second transfer amount from the pattern generator, calculates a difference between the first data amount obtained and the second data amount obtained, determines whether the difference calculated is within a predetermined range, and stops storing the internal states to the fine resolution data storage when it is determined that the difference is not within the predetermined range.