| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain contact information at a high sped short period with a simple configuration by decoding a plurality of contact switching states in which arrangement order of contacts representing a digit and sending/receiving a signal of the measurement unified standard obtained by applying D/A conversion to the data. SOLUTION: A D/A converter circuit 2 receives information of N-sets of contacts 11-1N arranged to equipment installation of a control object field and a transmission circuit 3 and a conversion control section 4 output a D/A converter output as a measurement unified signal of, e.g. 4-20mA. A reception circuit 7 is mainly made up of a level shift circuit and the measurement unified signal of, e.g. 4-20mA into a signal level receptible by an A/D converter circuit 8. The A/D converter circuit 8 has the same digit number as that of the D/A converter circuit 2 and the information of the contact switching state is outputted as binary data where the contact arrangement indicates a digit. Thus, the transmission of a contact switching state is equal to parallel transmission and contact information is obtained at a high speed for a short period. Since the measurement unified signal is used for the transmission system, the system is simply configured.</p> |
