FBM202 Field Wiring Remote I/O Subsystem Foxboro

Description

The interface between the I/O module PLC and the electrical circuit is completed through the input output part (I/O). The I/O module integrates the I/O circuit of the PLC, with the input register reflecting the status of the input signal and the output point reflecting the status of the output latch. The input module converts electrical signals into digital signals and enters the PLC system, while the output module is the opposite.

I/O is divided into modules such as switch input (DI), switch output (DO), analog input (AI), and analog output (AO). Switching quantity refers to a signal that only has two states: on and off (or 1 and 0), while analog quantity refers to a continuously changing quantity. The commonly used I/O classifications are as follows: switching value: divided by voltage level, there are 220VAC, 110VAC, 24VDC, and divided by isolation method, there are relay isolation and transistor isolation.

Analog quantity: Classified by signal type, there are current type (4-20mA, 0-20mA), voltage type (0-10V, 0-5V, -10-10V), etc. Classified by accuracy, there are 12bit, 14bit, 16bit, etc. In addition to the general IO mentioned above, there are also special IO modules such as thermal resistors, thermocouples, pulses, etc. Determine the module specifications and quantity based on the number of I/O points. I/O modules can be many or few, but their maximum number is limited by the basic configuration capabilities that the CPU can manage, that is, by the maximum number of backplane or rack slots.

The power module PLC power supply is used to provide working power for the integrated circuits of each PLC module. At the same time, some also provide 24V working power supply for the input circuit. The types of power input include: AC power supply (220VAC or 110VAC), DC power supply (commonly used as 24VAC).