DSQC661 3HAC026253-001 Power Module

DSQC661 3HAC026253-001 Power Module

DSQC661 3HAC026253-001 system through the two output points will display data in accordance with a certain time sequence to the digital display instrument.PLC system generally have relay output, silicon output, transistor output and 24V DC voltage output and other forms to choose from, generally use its transistor output or 24V output form through the corresponding conversion circuit to connect the digital display instrument.

In order to adapt to the two output forms, DSQC661 3HAC026253-001 adopts photocoupler to unify the PLC system output signal into TTL level signal. If the PLC system’s output form is 24VDC, such as Siemens S7 series PLC, the PLC output and photocoupler input side of the connection as shown in Figure 2. If the output of the PLC system is in the form of transistor open collector or open drain output, such as Mitsubishi’s FX series PLC, the connection between the PLC output and the input side of the opto-coupler is shown in Figure 3.

DSQC661 3HAC026253-001 No matter what connection method is used, the signal logic that enters the STC89C51 microcontroller after conversion is consistent with the output logic of the PLC system. The use of photocouplers to achieve signal conversion is conducive to improving the system’s anti-interference capability, because even if the interference signal has a high voltage amplitude, but its energy is relatively small, the formation of a weak current is generally not enough to make the photocoupler conductive [3]. The converted two signals are connected to the two external interrupt input pins of the microcontroller as data lines and clock lines, respectively, to facilitate the use of interrupt mode to transmit the display data.