Panel embedded sensor two-wire passive 4-20mA intelligent control LED digital display meter: SY LED2 series
SunYuan SY LED2 type low-cost, small volume two-wire passive intelligent loop 4-20mA current (LED) digital display meter, using passive design of the input and output two lines in series to access the transmitter 4-20mA loop, can be through the loop 4-20mA analog, according to the set range of linear correspondence to the decimal digital display. SY LED2 digital display meter adopts two-wire passive working principle, the electrical signal passed in the measuring circuit is not only the input signal of the display meter, but also the power supply of the display meter, this two-wire passive mode of operation does not need other auxiliary power supply, so it is easy and convenient to use the wiring, with small volume, high precision and low cost. The traditional analog display meter adopts potentiometer adjustment, which has a single adjustment parameter, is not flexible and is greatly affected by temperature. Compared with the traditional analog display meter, this digital meter adopts two-key operation and is controlled by the CPU of the central processor, which can realize the setting of various parameters such as zero point, full scale, decimal point, alarm, time delay and so on, and has strong flexibility and practicability. Digital display meter adopts LED display board, LED each segment adopts constant current drive, make 4-20mA range of brightness uniformity, and with reverse, overcurrent protection, suitable for industrial field, petrochemical industry, environmental monitoring, mining industry on the temperature, pressure, flow, level and other physical quantities of the control point monitoring 。In most applications, it is through a variety of related sensors will be temperature, pressure, flow, level and other physical quantities into 4-20mA signal, and then access to the SY LED2 digital display, temperature, pressure, flow, level and other physical quantities of real-time display, to facilitate the user to carry out a full range of on-site control.
SY LED2 digital display meter is used to measure 4-20mA DC current signal without external power supply directly on the 4-20mA loop signal to take power measurement. The displayed figure is not the direct current measurement value, but the preset value of 4mA and 20mA, and the measured current value is linearly displayed relative to these two preset values. For example, if 4mA is set to 0 and 20mA is set to 8000, the meter will display 2000 when 8mA is input, and 4000 when 12mA is input; and if 4mA is set to 1000 and 20mA is set to -1000, the meter will display 0 when 12mA is input, and -500 when 16mA is input.The maximum range of display of digital display meter is 9999 and the minimum is -1999.
SY LED2 digital display meter also has an alarm function with two isolated switching outputs for local display, control and alarm. This function is only realized from the program, 2 PC452 photocoupler pads position is reserved, to be installed when the user has the need for alarm. The digital display meter has two alarm points with positive and negative alarm direction settings. Alarm point of the alarm object for the display readings, the last decimal point of the LED panel flashes when the alarm, the alarm information through the port output can be driven optocoupler alarm signal.
SYLED2 adopts plastic casing, with an external dimension of 61.4×26.0mm and a thickness of 17.7mm, and is used for displaying the digital display of control instruments or variable signals inside the cabinet.
Precautions
1. Do not connect the input signal (current direction) inversely, otherwise the digital display meter will be easily damaged.
2, the input current signal is generally not more than 25 mA, when the input current reaches 100 mA, the digital display meter will be damaged immediately and irreparably.
When testing or accessing the current circuit, it is best to protect the circuit in series with a resistance of 200Ω or more.
3, can not be used in the humid and corrosive gas environment, otherwise it will reduce the service life or completely damaged.
