DSAI130D CB801 Analog input board 16 channels

Brand: ABB

Model: DSAI130D

Ship to: Demander’s destination

Warranty period: 12 months

Delivery period: 1-3 days

When the PLC is running, it completes the control task by executing the user program that reflects the control requirements. It needs to perform many operations, but the CPU cannot perform multiple operations at the same time. It can only perform one operation at a time in the time-sharing operation (serial work) mode, and execute one operation at a time, one by one in sequence. Since the CPU’s operation processing speed is very fast, from a macro point of view, the results that appear outside the PLC seem to be completed simultaneously (in parallel). This serial working process is called PLC scanning working mode.

When the user program is executed in the scanning mode, the scanning starts from the first program. Without interruption or jump control, the user program is executed one by one in the sequence of program storage until the program ends. Then start the scan from the beginning and run it again and again.

The scanning working mode of PLC is obviously different from the working principle of electrical control. The electrical control device adopts the hard logic parallel working mode. If the coil of a relay is powered on or off, all normally open and normally closed contacts of the relay will immediately act at the same time no matter where they are in the control circuit; The PLC adopts scanning working mode (serial working mode). If the coil of a soft relay is connected or disconnected, all its contacts will not act immediately, and they will not act until the scanning reaches this point. However, due to the fast scanning speed of PLC, there is usually no difference between PLC and electrical control device in I/O processing results.