Hardy HI 2151/30WC Single-Scale Controller - Manual (Page 171)

Appendix B - Glossary ot Terms
Preact The number of units above or below the set point value of which the relay will
trip. Use as an "in flight" compensation value.
Previous Key A key used to step back through menus.
Prompts Instructions or options presented, in a menu, by the instrument.
RAM Random-Access-Memory. Read/write memory out of which the microproces-
sor can both write and read data.
Rate of Change A measure of the rate at which weight is changing. For example, if 100
pounds were dispensed in 1 minute the rate of change would be 100 lb/
minute.
Relay Sense Selection Optional procedure which reverses the relay sense from normally energized
to normally de-energized, or back again.
Remote Function A function in the instrument that can be accessed away from the instrument.
Repeatability The maximum difference between readings for repeated readings under iden-
tical conditions.
ROM Read-Only-Memory. This permanent, non-volatile memory gives the proces-
sor instructions and cannot be altered.
RTS Request to send an RS-232C level, signaling a readiness to send.
RXD Received data at a serial port. Accepts RS-232C data signals.
Scale Capacity The maximum amount of weight the scale is capable of supporting, (Live load
plus deadload).
Secure Memory Module
(SMM) The Secure Memory Module stores and protects vital information from corrup-
tion, including calibration, configuration of setpoints, RS-232C Serial Port,
Optional Serial, BCD, Bar-graph, and Rate of Change. Also allows the trans-
ference of data from one unit to another, with no re-calibration or re-configura-
tion necessary.
Set Point Ordered weight of a particular ingredient. Weight reading at which a relay will
be actuated.
Span The total amount of test weights used (placed on the scale) when performing
a "Hard Calibration".
Tag Another name for Secure Memory Module.
Tare Artificial zeroing of the weight hopper so that a net weight can be displayed.
Also, the action of adjusting out the known weight of the container from the
total indicated weight, so that the indicator reads net weight directly.
Temperature Coefficient The change in indication due solely to a change in temperature from a refer-
ence temperature. Expressed as a percentage of span value for a specified
temperature change.
Time Base Time in seconds between values subtracted to determine rate of change.
Transmitter Span Value the transmitter puts out with the maximum weight on the load cell.
Transmitter Zero Value the transmitter puts out with minimum weight on the load cell.