Synchronization apparatus and field device

A field device having a detection unit configured to detect a physical quantity, performing signal process with respect to a detection signal output from the detection unit, and determining the physical quantity detected by the detection unit;

• the field device comprising:
• a first processing unit configured to perform a pre-processing on the detected signal output from the detection unit;
• a second processing unit configured to perform a post-processing on a signal from the first processing unit;
• a synchronization apparatus synchronizing an operation of the first processing unit and an operation of the second processing unit, the synchronization apparatus including:
• a counting unit configured to operate with a period that is sufficiently shorter than a period of a first reference signal that governs a timing of the pre-processing in the first processing unit, and outputting, when it has counted a target count value that has been set, a second reference signal that governs a timing of the post-processing in the second processing unit;
• a phase control unit configured to generate a control value for controlling a phase difference of the second reference signal with respect to the first reference signal in accordance with a count value of the counting unit when the first reference signal is input;
• and
• a filter unit configured to filter the control value that has been generated by the phase control unit so as to determine the target count value to be set in the counting unit;
• and
• a startup control unit that, when a difference between a first count value, which is a count value of the count unit when the first reference signal is input, and a second count value, which is a count value of the counting unit when the first reference signal is next input, is smaller than a pre-established threshold, sets the second count value to the target count value of the counting unit.

A synchronization method for synchronizing an operation of a first processing unit that performs a pre-processing on an input signal and an operation of a second processing unit that performs a post-processing on a signal from the first processing unit, the synchronization method comprising:

• operating with a period that is sufficiently shorter than a period of a first reference signal that governs a timing of the pre-processing in the first processing unit, and outputting, when counting a target count value that has been set, a second reference signal that governs a timing of the post-processing in the second processing unit;
• generating a control value for controlling a phase difference of the second reference signal with respect to the first reference signal in accordance with a count value when the first reference signal is input;
• filtering the control value that has been generated so as to determine the target count value to be set;
• and
• when a difference between a first count value, which is a count value when the first reference signal is input, and a second count value, which is a count value when the first reference signal is next input, is smaller than a pre-established threshold, setting the second count value to the target count value.