Vishay VT300 - Receiving Input from a Scale; Displaying and Manipulating Weight Information; Sending Output to Other Devices; Product Features

Introduction
Product Features
VT300 User’s Guide, Rev. A4 16 Doc # UM-VT300-EN
1.1.1 Receiving Input from a Scale
A scale is designed to send out an electrical signal when weight is applied to its
weighing platform. The heavier the item being weighed, the stronger the signal. An
indicator like VT300 receives this signal and uses it to calculate the weight of the
item. To do this, it must be connected to the scale and properly calibrated.
Calibration, which may only be performed by authorized technicians, tells the
indicator the minimum and maximum weight the scale can handle, and the
corresponding electrical signal for each of these extremes. This allows the indicator to
translate an electrical measurement into actual weight in kilograms or pounds.
1.1.2 Displaying and Manipulating Weight Information
The basic operation of VT300 is to display the weight of the item that is currently on
the platform. This information can be saved to non-volatile memory called Alibi
Memory, and retrieved later.
If you provide more information, VT300 can do more than just display the current
weight. It can deduct the weight of the container (taring); calculate the number of
units being weighed; and calculate an average weight for the units being weighed.
1.1.3 Sending Output to Other Devices
In addition to showing and manipulating weight information, VT300 can send it to
other devices using its two serial ports. In a typical setup, the indicator is connected
to a printer, allowing you to print out weight information in several formats.
It is also possible to connect the indicator to a personal computer, which allows more
powerful data processing, or to an external display, which allows weight information
to be viewed in a larger format or at a distance from the indicator itself.
VT300 also has two analog setpoints, with corresponding weight thresholds. When
the item being weighed exceeds one of these thresholds, the relevant setpoint can
trigger an event in your production process.
Only authorized technicians may connect the indicator to external devices such as the
ones listed above.
1.2 Product Features
 High accuracy analog-to-digital converter (max 550,000 internal counts).
 Front panel with 16 character (14.5mm height) LCD display module.
 27-key membrane keyboard with tactile feedback.
 32 KB Flash RAM, real-time clock and non-volatile memory for system parameters
and calibration data.
 Flash memory storing up to 10,000 weights (electronic tally roll or Alibi memory).