Page 16
ST 800 Series HART/DE Option User’s Manual
Revision 5.0
DE-Specific Configuration Parameters
Select the
Configure
button, and configure parameters according to Table 6.
Table 6 – DE Configuration Parameters
Parameter
Read (R) or
Read/Write (R/W)
Configuration Details
LRL
R
Lower Range Limit, Floating Point
URL
R
Upper Range Limit, Floating Point
LRV
R/W
Lower Range Value, Floating Point
URV
R/W
Upper Range Value, Floating Point
PV Units
R/W
Process Variable Units: scaling value selection; default = inches
H
2
0@39
o
F
SV Units
R/W
Secondary Variable scaling units:
o
C or
o
F
Sensor Type
R
Sensor type used in the Transmitter
Damping
R/W
Select digital noise reduction; (see note below)
Span
R
Process Range: URV – LRV, Floating Point
Conformity
R/W
Conformity: for the output calculation. Linear (pressure) or Square
Root (flow); (see note below)
Select the Back button to go back to the DE MAIN MENU.
Notes on Damping (Digital Noise Reduction)
You can adjust the damping time to reduce output noise. By way of suggestion, set damping to the
smallest value reasonable for your process.
The electrical noise effect on the output signal is partially related to the turndown ratio of the
Transmitter. As the turndown ratio increases, the peak-to-peak noise on the output signal increases.
You can use the following formula to find the turndown ratio using the range information for your
Transmitter.
Turndown Ration =
Upper Range Limit
(Upper Range Value
−
Lower Range Value)
Note that ST 800 Transmitters are specified with a minimum of 100:1 turndown capability.
