Siemens SITRANS LUT400 Series Operating Instructions Manual page 485

2.9.2. Discrete Input Logic
Use the following parameters to configure the discrete input itself.
Normal state is standard operation, with the SITRANS LUT400 sensing the
material level and controlling the pumps, and no faults or alarms present. The
discrete input contacts are either NORMALLY OPEN or NORMALLY CLOSED
when the system state is normal.
Discrete Input Logic
Normally Open
Normally Closed
For example:
When discrete input logic is set to Normally Open and discrete input has no
voltage applied on the terminal block, the discrete input will be inactive (OFF).
2.9.2.1.
Use to change the behaviour of the Discrete Input 1.
Options
2.9.2.2.
Read only. Indicates the current state of Discrete Input 1.
Options
2.9.2.3.
Use to change the behaviour of Discrete Input 2.
Options
2.9.2.4.
Read only. Indicates the current state of Discrete Input 2.
Options
Page 172 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS
Terminal Block
Voltage applied
No voltage applied
Voltage applied
No voltage applied
Discrete Input 1 Logic
Discrete Input 1 Scaled State
Discrete Input 2 Logic
Discrete Input 2 Scaled State
Discrete Input Scaled State
ON
OFF
OFF
ON
*
NORMALLY OPEN
NORMALLY CLOSED
ON
*
OFF
*
NORMALLY OPEN
NORMALLY CLOSED
ON
*
OFF
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