User's Manual

Service and troubleshooting
Instruction manual 973 SmartRadar LT Page 39
Item Name Description
W2
= Protection level 2 Enter password 2.
CZ
Clear min max diagram Clears all elements of item
4T
by writing 30 in them (sets
4T
to
H
default).
EX
Exit Exit protection level.
4.4 Alarm loop checking
Normally, level alarms can be verified when the level reaches the low level or high level alarm set point.
The level alarms and, if applicable, the hard alarm contact coupled to one of the level alarms, can be
checked by a “loop check” command. This is independent of the actual level value.
The level alarm signalling can be checked in several ways:
• via the communication line to the host
• via the hard alarm output contact
When enabled, the alarm test (item
AT
) can be given. The specified alarm is then toggled for one minute.
Item
AT
has 8 positions; four character pairs are used to specify the desired alarm for testing: HH, HA, LA
and LL. Each alarm can be tested individually, or the alarms can be tested simultaneously.
Item Name Description
LE
Loop check enable The loop check enable item enables or disables the alarm test
with item
AT
.
• E : enables alarm test with item
AT
• D : disables alarm test with item
AT
If the alarm test is required, check if item
LE
is set to “E”.
If item
LE
is set to “D”, change the setting to “E”.
AT
= Alarm test The alarm test item toggles the specified level alarm for one
minute. The settings for the alarms to be tested are as follows:
aabbccdd (8 ASCII characters)
where:
aa : HH high high level alarm test
- - no high high level alarm test
bb : HA high level alarm test
- - no high level alarm test
cc : LA low level alarm test
- - no low level alarm test
dd : LL low low level alarm test
- - no low low level alarm test
For example:
AT= - - HALA - -
toggles the high and low level alarm for one minute.
Note:
When, as in the above example, a high and low alarm are toggled at the same time, the high alarm
prevails over the low alarm on the communication line. It is therefore recommended to check only one
alarm at the time.