AMALGAMATED INSTRUMENT RM4-IV, Operation And Instruction Manual

Page: 20 / 49

5.6 Alarm relay reset time
Display:
A
x
rt
Range:
0
to
9999
Default Value:
0
Displays and sets the alarm reset delay time in seconds. The reset time is common for both alarm
high and low setpoint values. With the alarm condition is removed the alarm relay will stay in
its alarm condition for the time selected as the reset time. If the input moves back into alarm
condition during this period the timer will reset and the full time delay will be restored. The reset
time is selectable over
0
to
9999
seconds. To set a reset time value go to the
A
x
rt
function and
use the
^
or
v
push buttons to set the value required then press
F
to accept this value.
Example: If
A1rt
is set to
10
seconds then the resetting of alarm relay 1 will be delayed by 10
seconds.
5.7 Alarm relay normally open/closed
Display:
A
x
n.o
or
A
x
n.c
Range:
A
x
n.o
or
A
x
n.c
Default Value:
A
x
n.o
Displays and sets the setpoint alarm relay x action to normally open (de-energised) or normally
closed (energised), when no alarm condition is present. Since the relay will always open when power
is removed a normally closed alarm is often used to provide a power failure alarm indication. To
set the alarm relay for normally open or closed go to the
A
x
n.o
or
A
x
n.c
function and use the
^
or
v
push buttons to set the required operation then press
F
to accept this selection. Example:
If set to
A1n.o
alarm relay 1 will be open circuit when the display is outside alarm condition and
will be closed (short circuit across terminals) when the display is in alarm condition.
5.8 Alarm relay setpoint or trailing operation
Display:
A
x
SP
or
A
x
t1
etc.
Range:
A
x
SP
or
A
x
t1
etc.
Default Value:
A
x
SP
Relay operation independent setpoint or trailing setpoint, this function only be seen where more
than one relay is fitted. Each alarm relay, except relay 1, may be programmed to operate with
an independent setpoint value or may be linked to operate at a fixed difference to another relay
setpoint, known as trailing operation. The operation is as follows:
Alarm 1 (
AI
) is always independent. Alarm 2 (
A2
) may be independent or may be linked to
Alarm 1. Alarm 3 (
A3
) may be independent or may be linked to Alarm 1 or Alarm 2. Alarm 4
(
A4
) may be independent or may be linked to Alarm 1, Alarm 2 or Alarm 3. The operation of
each alarm is selectable by selecting, for example, (Alarm 4)
A4.SP
= Alarm 4 normal setpoint
or
A4.t1
= Alarm 4 trailing Alarm 1 or
A4.t2
= Alarm 4 trailing Alarm 2 or
A4.t3
= Alarm
4 trailing Alarm 3. For trailing set points the setpoint value is entered as the difference from the
setpoint being trailed. If the trailing setpoint is to operate ahead of the prime setpoint then the
value is entered as a positive number and if operating behind the prime setpoint then the value is
entered as a negative number.
20 of 49 RM4IVMAN-2.1-0