System for sending signals between modules

A system for transmitting signals between monitors, comprising a sending-side module for transmitting a pulse signal of a specific period that indicates the existence of data, and a receiving-side module that detects the existence of the data by receiving the pulse signal that is transmitted from the sending-side module, wherein:

• the sending-side module comprises:
• a plurality of signal generating units, provided in parallel, for generating the pulse signal through time division;
• a pulse signal synthesizing unit for combining into a single time series pulse signal the pulse signals generated by each of the individual signal generating units;
• an output circuit, made from a relay that, when not driven, connects between a common terminal and a normally-closed terminal, and, when driven, connects between the common terminal and a normally-open terminal, to input, into the common terminal, the pulse signal that has been combined into a single signal by the signal synthesizing unit, and to output this pulse signal from the normally-open terminal towards the receiving-side module;
• and
• a relay driving unit for driving the relay only when all of the plurality of signal generating units are operating to generate the pulse signals;
• and wherein
• the plurality of signal generating units operates cooperatively in each generating the pulse signals, and detects whether or not the pulse signal is at the normally-open terminal of the relay and detects whether or not the pulse signal is at the normally-closed terminal of the relay, to evaluate a failure of the pulse signal that is outputted to the receiving-side module, to stop the generation of the pulse signal if a failure is detected.