Siemens SITRANS FST030 - Page 184

Modbus
register
Data type /
Size in bytes
Parameter Description Default value
[units]
(units register)
Value range /
Setting options
Access
level
7403 Float / 4 Upper warning
limit
Exceeding this limit
causes a warning.
max. mass
flow
[kg/s]
(7400)
-max. mass flow -
+max. mass flow
Read /
write
7405 Float / 4 Lower warning
limit
Falling below this limit
causes a warning.
-max. mass
flow
[kg/s]
(7400)
-max. mass flow -
+max. mass flow
Read /
write
7407 Float / 4 Lower alarm
limit
Falling below this limit
causes an alarm.
-max. mass
flow
[kg/s]
(7400)
-max. mass flow -
+max. mass flow
Read /
write
7412 Float / 4 Hysteresis Hysteresis that affects
the alarm and warning
limits.
0
[kg/s]
(7400)
0 - max. mass flow Read /
write
Standard volume flow settings
Table A-31 Standard volume flow settings (only hydrocarbon applications)
Modbus
register
Data type /
Size in bytes
Parameter Description Default value
[units]
(units register)
Value range /
Setting options
Access
level
1723 Float / 4 Standard condi‐
tion temperature
Specifies temperature
for standard conditions.
The value is used to cal‐
culate standard proc‐
ess values.
15.0
[°C]
(7700)
0.0 - 100.0 Read /
write
1725 Float / 4 Standard condi‐
tion pressure
Specifies pressure for
standard conditions.
The value is used to cal‐
culate standard proc‐
ess values.
101325
[Pa]
(8015)
100000.0 - 200000.0 Read /
write
1731 Float / 4 Standard condi‐
tion air density
Specifies air density for
standard conditions.
The value is used to cal‐
culate standard proc‐
ess values.
1000.0
[kg/m
3
]
(7600)
0.080 - 10000.0 Read /
write
7531 Float / 4 Low flow cut-off Standard volume flow
limit for low flow cut-off.
Below limit standard
volume flow output is
forced to zero.
0.0
[Sm
3
/h]
(7964)
0 - max. standard volume
flow
Read /
write
7952 Float / 4 Upper alarm
limit
Exceeding this limit
causes an alarm.
max. stand‐
ard volume
flow
[Sm
3
/h]
(7964)
-max. standard volume
flow -
+max. standard volume
flow
Read /
write
Modbus communication
A.9 Modbus holding registers tables
SITRANS FST030 (Modbus)
184 Operating Instructions, 08/2018, A5E37367739-AD