Endress+Hauser NRF81 - Page 139

Tankside Monitor NRF81 Operating menu
Endress+Hauser 139
Operating mode (→  138) Direction of signal Type of signal
4..20mA output Output to higher-level unit Analog (4...20mA)
HART slave +4..20mA output Output to higher-level unit • Analog (4...20mA)
• HART
Depending on the terminals used, the Analog I/O module is used in the passive or active
mode.
Mode Terminals of the I/O module
1 2 3
Passive
(power supply from external source)
- + not used
Active
(power supplied by the device itself)
not used - +
In the active mode the following conditions must be met:
• Maximum current consumption of the connected HART devices: 24 mA
(i.e. 4 mA per device if 6 devices are connected).
• Output voltage of the Ex-d module: 17.0 V@4 mA to 10.5 V@22 mA
• Output voltage of the Ex-ia module: 18.5 V@4 mA to 12.5 V@22 mA
Current span 
Navigation  Setup → Advanced setup → Input/output → Analog I/O → Current span
Prerequisite Operating mode parameter (→  138) ≠ Disabled option or HART master option
Description Defines the current range for the measured value transmission.
Selection • 4...20 mA NAMUR
• 4...20 mA US
• 4...20 mA
• Fixed current
Factory setting 4...20 mA NAMUR
Additional information
Read access Operator
Write access Maintenance
Meaning of the options
Option Current range for process
variable
Lower alarm signal level Upper alarm signal level
4...20 mA 4 to 20.5 mA < 3.6 mA > 21.95 mA
4...20 mA NAMUR 3.8 to 20.5 mA < 3.6 mA > 21.95 mA