Endress+Hauser NRF81 - Page 76

Commissioning Tankside Monitor NRF81
76 Endress+Hauser
9.2.14 Configuration of the HART slave + 4-20mA output
If Operating mode = HART slave +4..20mA output has been selected for an Analog I/O
module, it serves as a HART slave which sends up to four HART variables to a HART
master.
The 4-20 mA signal can be used in this case, too. For its configuration: →  75
Standard case: PV = 4-20mA signal
By default, the Primary Variable (PV) is identical to the tank variable transmitted by the
4-20mA output. To define the other HART variables and to configure the HART output in
more detail, proceed as follows:
1. Navigate to: Setup → Advanced setup → Communication → HART output
→ Configuration
2. Go to the System polling address parameter and set the HART slave address of the
device.
3. Use the following parameters to assign tank variables to the second to fourth HART
variable: Assign SV, Assign TV, Assign QV.
 The four HART variables are transmitted to a connected HART Master.
Special case: PV ≠ 4-20mA signal
In exceptional cases it might be required that the Primary Variable (PV) transmits a
different tank variable than the 4-20mA output. This is configured as follows.
1. Navigate to: Setup → Advanced setup → Communication → HART output
→ Configuration
2. Go to the PV source parameter and select Custom.
 The following additional parameters appear in the submenu: Assign PV, 0 %
value, 100 % value and PV mA selector.
3. Go to the Assign PV parameter and select the tank variable to be transmitted as the
Primary Variable (PV).
4. Use the 0 % value and 100 % value parameters to define a range for the PV. The
Percent of range parameter indicates the percentage for the actual value of the PV.
It is included in the cyclical output to the HART master.

1
B
A
0%
2
100%
[%]
PV
A0032954
 37 Scaling of the tank variable to the percentage
A 0 % value
B 100 % value
1 Primary variable (PV)
2 Percent of range
5. Use the PV mA selector parameter to define whether the output current of an
Analog I/O module is to be included in the cyclical HART output.