EN 
ES FAQs
General
� Why can't my scale be powered on?
Check whether AC adapter or batteries have been correctly installed.
� What type of display works better with battery power? Why?
LCD – low power consumption and long battery life.
� What are the differences between LED, LCD, and VFD displays?
Light Emitting Diode (LED) and Vacuum Fluorescent Display (VFD) display types are recommended for indoor applications, identifiable by digits that light up over a dark background. For most applications in sunlight, we suggest a Liquid Crystal Display (LCD), which is identifiable by black digits over a gray (or backlit) background.
About Communication
� How far does RS-232 travel?
Because of sensitivity to noise, RS232 is not recommended for applications requiring more than 50 feet of travel.
� Which would travel farther in RS-232, 9600 or 1200 baud?
In this case 1200 baud. In general, slower baud rates will travel greater distances.
Technical Knowledge
� What is an analog output and where is it used?
A continuous variable voltage (0-10V) or current (4-20ma) output that tracks the weight applied to the scale. Analog outputs are commonly used to communicate with a PLC.
� What is the purpose of the A/D converter?
-To convert an analog signal (like the signal from a load cell) to a digital signal that can be displayed as a value.
� What is the purpose of sensing?
Running a load cell cable over longer distance and exposing it to severe temperature change can impact the resistance within the cable and ultimately the accuracy of the scale. Therefore, sense lines are used to help the A/D monitor exactly how much excitation voltage is at the load cell and maintain accuracy for the entire system.
� What do EMI and RFI stand for?
These are two types of interference. Electro Magnetic Interference (EMI) comes from industrial type equipment with large coils or motors. Radio Frequency Interference (RFI) comes from transmitting devices such as radios and cell phones.
About Standards
� What is a Class III application?
Handbook 44 separates weighing devices into five accuracy classes according to number and value of scale divisions–I, II, III, IIIL, and IIII with class I having the highest precision. Class III implies all commercial (Legal-for-Trade) weighing devices including grain-test scales, jewelry scales, animal scales, postal scales, and laundry scales. A produce scale would be one type of class III application, while truck scales fall under class IIIL, high-precision jewelry scales Class II, and precision laboratory weighing Class I.
� What is NTEP?
National Type Evaluation Program (NTEP) certification allows a weighing device to be used for commercial and Legal-for-Trade applications, implying that it is capable of meeting standards put forth in the NIST Handbook 44.
