Modbus register assignment of the ISOMETER®
55
isoRW425_D00052_04_M_XXEN/03.2019
8.1.2.2
AT&T = Alarm type and test type (internal/external)
The alarm type is coded by bits 0 to 2. Bits 3, 4 and 5 are reserved and always
have the value 0. Bit 6 or 7 is usually set when an internal or external test has
been completed. Other values are reserved. The complete byte is calculated
from the sum of the alarm type and the test type.
Bit
7
6
5
4
3
2
1
0
Meaning
Te
st
e
x
te
rn
a
l
T
e
st
in
te
rn
al
Reser
v
ed
Reser
v
ed
Reser
v
ed
Ala
rm
Er
ro
rs
Al
a
rm
t
y
p
e
X
X
X
X
X
0
0
0
No alarm
X
X
X
X
X
0
0
1
Prewarning
0
0
X
X
X
0
1
0
Device error
X
X
X
X
X
0
1
1
Reserved
X
X
X
X
X
1
0
0
Warning
X
X
X
X
X
1
0
1
Alarm
X
X
X
X
X
1
1
0
Reserved
X
X
X
X
X
…
…
…
Reserved
X
X
X
X
X
1
1
1
Reserved
Te
st
0
0
X
X
X
X
X
X
No test
0
1
X
X
X
X
X
X
Internal test
1
0
X
X
X
X
X
X
External test