![background image](http://html1.mh-extra.com/html/extech-instruments/48vtr/48vtr_instruction-manual_2452980005.webp)
48VTR English 9/00 Ver. 2.7
4
5.3 Status Indicators
'ALM' Status Indicator (
Alarm Relay Status LED)
This LED is lit in red when the Alarm relay is active. Also, this LED flashes when
the Alarm is configured as an Event/Soak timer and is in the process of counting
down. Refer to Appendix A for more on Alarm Functions.
'OUT' Status Indicator
(Control Output Status LED)
Illuminates in green when the control output is active.
AUTO TUNE Status Indicator
When the controller is auto tuning, the rightmost decimal on the green LED
display will blink on/off. When the meter is finished tuning, the decimal will cease
blinking and disappear. Auto Tuning may take from several minutes to several
hours depending upon the process in question. See section 9.2 for details on
Auto Tune.
LED Error Messages:
Err 1
: A/D converter is inoperable. Unit must be repaired or replaced.
uuuu
: Over range condition with regard to input signal.
nnnn
: Under range condition with regard to input signal.
- - - -
: Input sensor not connected or is inoperable.
5.4 Keypad Descriptions
SCROLL Key
Press once to access the programming mode’s first level. In programming mode,
move from one programmable parameter to the next by pressing the SCROLL
key. The SCROLL key is also used in combination with the RETURN key to move
between programming levels. The red LED display will show each parameter
title as you scroll through the list. Also, to activate an autotuning session, press
and hold the SCROLL key for 5 seconds.
UP Arrow Key
Increases the Setpoint (SV). Also increments parameter data when
programming.
DOWN Arrow Key
Decreases the Setpoint (SV). Also decrements parameter data when
programming.
RETURN KEY
During normal operation, pressing the RETURN key permits the user to view the
controller output action as a percentage (0.0-100.0%). Press this key from any
other mode to return to the normal SV display. The RETURN key is also used
with the SCROLL key (pressed simultaneously) to move from one programming
level to another.