How do you scale analog value in PLC?
How do you scale analog value in PLC?
Formulate a scaling equation to program into the PLC so that 4 mA of current registers as 0 GPM, and 20 mA of current registers as 700 GPM. We are already given the raw number values from the analog card’s analog-to-digital converter (ADC) circuit for 4 mA and 20 mA: 3277 and 16384, respectively.
How is scaling done in PLC?
Scaling is the process of taking a signal such as a process variable, voltage or current output from a sensor and applying calculations to present this signal in a more usable form in terms of engineering units, such as PSI, °F or %RH to the operator in the control room.
What is scaling and Unscaling in PLC?
Analog Input-Output Scaling It means when the operator gives a command to open the valve at 0%, the PLC sends an electrical signal of 4 mA to the valve. FC106, unscaling block, converts the real value of 0% to 100% into 0 to 27648 integer value and provides an analog output signal of 4-20 mA to the valve.
How do you do analog scaling?
y=mx+b can be used to scale your raw data of an analog input to the engineering units of the analog sensor that is connected to it or your engineering units of an analog output to the raw data that an analog output module requires. y – This will be the scaled result.
How do you scale a 4 20mA signal?
Solution: Take 10.6 milliamps and subtract the LRV (4 milliamps), then divide by the span (16 milliamps) to arrive at 41.25% (0.4125 per unit). lastly add the LRV of the pressure range (150 PSI) to arrive at a final answer of 253.125 PSI.
How do you scale analog input data?
What is scaling in Scada?
Scaling allows the raw signal values from plant to be scaled into more appropriate values for use within Geo SCADA Expert and vice versa. You typically configure scaling on the tab of the appropriate Analog Point Form.
How is mA current calculated?
A milliamp is one one-thousandth of an amp. By calculating the value in amps and dividing by one thousand, you will have a value of current in milliamps.
How many Ma does a PLC convert analog to digital?
PLC Analog Input Scaling An Allen-Bradley SLC500 programmable logic controller (PLC) uses a 16-bit analog-to-digital converter (in its model 1746-NI4) in analog input card to convert 4-20 mA signals into digital number values ranging from 3277 (at 4 mA) to 16384 (at 20 mA).
What is the minimum and maximum input value in AB plc?
Minimum Input value (Ex: 4 to 20 mA from level transmitter means 4 mA is the input minimum value) Maximum Input value (Ex: 4 to 20 mA from level transmitter means 20 mA is the input maximum value) Minimum scale value (0 to 32767 is the maximum positive acceptable number in AB PLC-Minimum Scaled value is 0)
How to scale from 4-20mA to 0%?
Depending on what SLC 500 series you have, you may use direct SCP instruction to scale your 4-20mA to 0-100%. However, if the SLC can’t directly perform the SCP, you may use the SCL instruction, where: I hope this can help.
How can I program 700 GPM flow into a PLC?
However, these raw numbers from the PLC’s analog card must be mathematically scaled inside the PLC to represent real-world units of measurement, in this case 0 to 700 GPM of flow. Formulate a scaling equation to program into the PLC so that 4 mA of current registers as 0 GPM, and 20 mA of current registers as 700 GPM.
