58
59
7. Alarm relay
This controller features a separate alarm relay. When the alarm is activated, the
red alarm LED will light on the controller and the ERR indicator will appear on
the controller display. The ATC and ERR indicators will blink if the error is due to
temperature measurement. Additionally, you can hook a separate visual or audible
alarm to this relay.
IMPORTANT: The alarm relay functions as an “Active Low” device; e.g. it switches
OFF under alarm condition. Therefore the alarm display device should be connected
to the “NC” contacts of the relay.
Delaying alarm relay action
Delay relay activation by 0 to 2000 seconds (factory default is 0 seconds).
See section 6.7.1 on page 50 for information on how to set an alarm delay.
mA
1
2
3
AC: L
N PE
4
5
6
7
8
9
10 11 12
13
14
15
16
17
–
+
Signal
Output
Hold
Input
Alarm
Relay
2
Relay
1
Power
Mains
10.
Alarm relay resting position
11.
Alarm relay common
12.
Alarm relay working position
8. Taking measurements
In normal measurement mode, the
display will appear as shown in the
figure at right.
The readings that appear depend on
the range selected (see section 6.6.1
on page 45). A range number
corresponding to the range you are
in appears in the lower left hand
corner of the display.
If ATC is selected on, the ATC
indicator should be lit. If manual
temperature selection is chosen, the
ATC annunciator will be off. When
the controller is in ATC mode, and the
temperature sensor wire is broken or
disconnected, an error message will
be displayed, plus the alarm LED
indicator and relay will be activated.
When taking resistivity readings, A m
Ω
indicator appears on the display, but is
equivalent to M
Ω
.
C
µ
S
ATC
READY
MEAS
