ABUS Technologies A1500 Universal Process Indicator - Manual (Page 15)

ABUS TECHNOLOGIES INC.
15
A1500
8.2 SPECIAL FUNCTIONS
8.2.1 Maximum and Minimum
The indicator memorizes the measured maximum and minimum values (peak and valley).
These two values are shown by pressing either the MAX or MIN keys. Pressing both keys
simultaneously will clear the memory for a new peak and valley detection.
8.2.2 Special Function Key and Digital Input
The F key (special function key) in the frontal panel and the optional digital input can execute
special functions according to the user selection. Figure 8 shows how to activate the digital input. The
special functions for the F key and for the digital input are explained as it follows.
KOLD - FREEZE MEASURED VALUE
The hold function freezes the measured value showed in the display. Each time the F key or
the digital inputs are selected, alternates from hold to normal mode. Whenever the indicator is in the
hold mode a “koLd” message is briefly displayed to show the operator that the displayed value is the
frozen value and not the present reading.
PKOLD - MAXIMUM VALUE
The Peak Hold function shows the maximum value measured since the last time the F key was
pressed or the digital input activated. Each activation of the F key or digital input triggers a new Peak
Hold cycle and the display resets with a new peak value.
RESET - CLEARS MAXIMUM AND MINIMUM
This function works the same way as the MAX and MIN keys pressed simultaneously, as
explained in the 5.1 section. If this “reset” function is programmed, every touch of the F key or activation
of the digital input will clear the memory and a new cycle of maximum and minimum values memorization
will start.
8.2.3 Process Variable Retransmission
As an option, the indicator can be supplied with an isolated 0-20mA or 4-20mA analog output
for Process Variable (PV) retransmission. The PV values that define the range of the 0mA/4mA to 20mA
retransmission can be programmed by the user in the high and low indication limits, at configuration
level. When this option is available, retransmission will be always active, so that the user will not be
required to turn it on or off. For a voltage output signal an external shunt (calibrated resistor) should be
installed at the analog output terminals.
8.2.4 Extra 24 Vdc Power Supply – Extra P.S
The indicator provides a voltage power supply of 24 Vdc to excite the field transmitters with 25
mA current capacity. It is available at the 16 and 17 terminals at the back panel.
8.2.5 Customized Linearization
Three types of signals can be user-customized to fit special linearization profiles. This means
that the operator can configure the instrument to read non-standard crescent non-linear signals with
high accuracy.