ParTech 7200, Instruction Manual

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7200 Monitor Instruction Manual
10 Alarm outputs
The 7200 Monitor has two alarm outputs designated Alarm 1 and Alarm 2. Each alarm has a single pole changeover
output that signals the alarm condition. During normal operation when the alarm is not active the alarm output will be in
its NORMAL condition, the N/O (normally open) contact will be open and the N/C (normally closed) contact will be
closed. When the alarm is active the alarm output will be in its ALARM condition and therefore the N/O contact will be
closed and the N/C contact will be open.
Note: The alarm output will enter its ALARM condition if the power to the instrument is disconnected.
The alarms are identical and therefore the configuration procedure is the same for each and is carried out as
described in the following sections:
10.1 Alarm Value
The alarm value can be set to any value within the currently selected measuring range (Sensor Menu). The value can
be set using the

keys, press OK to accept the new value or MENU to cancel and exit.
Note: The value can only be set within the range of the selected sensor range.
10.2 Alarm Type
The alarm type can be selected from the following:
Off
If the alarm is set to OFF, the output will remain in its NORMAL condition whilst the instrument is switched on
regardless of the measured value and other alarm settings.
Low
The output will go into the ALARM condition whenever the measured value is less than or equal to the alarm value.
The output will return to its NORMAL condition when the measured value is greater than the alarm value.
High
The output will go into the ALARM condition whenever the measured value is greater than or equal to the alarm value.
The output will return to its NORMAL condition when the measured value is less than the alarm value.
Fault
When the alarm type is set to fault, the alarm output will enter the ALARM condition when any of the selected faults
occur. The output will return to its NORMAL condition when all the selected faults are not active.
10.3 Alarm Hysteresis
In a normal condition an alarm turns on and off at the same value. For example, if a high alarm turns on at 2000mg/l
the alarm occurs when the reading increases to 2000mg/l. When it decreases through 2000mg/l the alarm turns off.
Some applications may demand that the alarm turns off at a different value, for a high alarm this would be value lower
than the alarm value, and for a low alarm this would be a value higher than the alarm value.
The hysteresis value determines the difference between the alarm switch on point and the alarm switch off point. In
the case of a high alarm, hysteresis causes the alarm to turn off at a value that is less than the alarm value. For a low
alarm, hysteresis causes the alarm to turn off at a value greater than the alarm value.
Page 22 of 50 167300IM-Issue 12 Issue Date 14/10/2014