The 1756-EN2TXT uses a single-task clock scanning or monitoring programme (with the exception of certain high-grade PLCs, such as Siemens’ S7-300/400 series, Rockwell’s ControlLogix series, etc.) to handle the logic operation instructions of the programme itself as well as the status acquisition and refreshing of the external I/O channels, and the whole application programme is contained in a single loop cycle.

1756-EN2TXT in a control system, although there are some process quantities of real-time requirements are very high, but at the same time there are more process quantities of real-time does not have special requirements, if the same refresh rate to deal with them in fact, is a waste of system resources, and the cycle scanning operation mechanism also leads to the system’s processing cycle is mainly dependent on the size of the application program, such as program complexity If the programme is complex and large, the scanning cycle is inevitably longer, which is undoubtedly contrary to the high real-time requirements of the I/O channel.

The 1756-EN2TXT is widely used in frequency and phase measurement and PWM (Pulse Width Modulation) applications that require extremely high accuracy in time processing. In addition, the main board of the CPU integrates a variety of communication interfaces, and the PCC is also a highly open product configured with a variety of communication modules. all the digital inputs of the PCC have been isolated by opto-electrical coupling, and the analogue inputs have been processed by RC filtering, so it has a very good ability to resist electromagnetic interference.