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Question:

PLC digital output relay output What is the difference! Where are the numbers used primarily?

PLC digital output relay output What is the difference! Where are the numbers used primarily?

Answer:

Relay output This is a quantitative output, that is, the so-called switch output, also known as DO Usually the PLC output output is divided into relay output or transistor output or thyristor output Transistor output is divided into NPN or PNP type, that is, NPN and PNP-type transistor of the sub-method Relay output can be AC-DC general, usually on the drive voltage is not mandatory, a few volts to two hundred volts can be, because it is a mechanical switch Transistor output for DC load, high-speed output pulse signal for servo motor drive pulse signal given and the like, NPN type is pulled low effective, commonly known as negative logic; PNP type is set to high effective, also known as positive logic Thyristor output for AC load, there are zero-point to turn off the characteristics of this is not commonly used
May 9, 2017
PLC output relay and transistor, I do not know your digital output is not referring to the transistor output. The main difference between the two is: 1. The relay output is a real physical relay, the output is the contact signal (NO or NC), while the transistor is no actual contact, but the output image.
May 9, 2017
2. Because the relay output is the contact, as long as the COM bit connected to any form of power (except for high voltage), then the contact can be output on the corresponding power supply. While the transistor output only a specific source (usually DC0V (relative to DC24V) or DC24V), the implementation of the component power supply is not necessary to an external relay. 3. Relay output response speed is much slower than the transistor, such as high-frequency control, the relay output powerless.
May 9, 2017

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