云南福利彩票快乐十分历史开奖结果safe digital and analog i/o modules are available with ip20 or ip67 protection. in addition to their normal i/o tasks, they also monitor the signal line as well as the connected sensors and actuators. because they are integrated within the entire system, they initially function in the standard application as normal modules. they deliver input signals and process output commands. only when used together with safelogic,do their safety-related characteristics become evident.