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12

 

User Guide

Safety function

The laser level transmitter produces an analog signal, between 4 mA and 20 mA, proportional to the 
level, volume or ullage, as defined by the operator. The analog signal is fed to a downstream logics 
unit such as a PLC or a limit signal generator, and is monitored for exceeding a specified maximum or 
minimum value. All safety functions refer exclusively to this analog output. The total valid range of the 
output signal shall be configured to a minimum of 3.8 mA and a maximum of 20.5 mA (factory defaults). 

The LLT100 provides the following Type-B safety functions:

•  Computes a distance/level measurement.
•  Outputs a 4–20 mA signal of the transformed measurement.
•  Measurement transformations are user-defined (math functions). These functions can be either on 

or off. Multiple parameters can be set related to:

 

– Damping

 

– Linearization function

 

– Filtering

The safety related function of the transmitter is the safe monitoring of the level within an accuracy of 

2% of span (2% of 16 mA). The safe state output current can be configured to be ≤3.6 mA (low alarm) or 
≥21.0 mA (high alarm), with the exception of CPU faults where the current output is in low alarm mode 
(≤3.6 mA).

There are other functionalities of the LLT100 that are not considered as part of the safety function:

•  Digital input (optional, external)
•  HART communication
•  HMI (optional)
•  Remote display (optional accessory)
•  Other accessories: lens heater, dust tube

Alarm response and current output

In case of detected critical faults, the configured alarm current will be produced and fed to a 
subsequent logic unit, e.g., a DCS, and monitored for violation of a defined maximum value.

Selectable alarm current modes

There are two selectable modes for this alarm current:

•  HIGH (max alarm current) which is the factory default setting;

or

•  LOW (min alarm current).

Configurable alarm currents

The low alarm current is configurable from 3.5 to 3.6 mA with a factory default setting of 3.6 mA. The 
high alarm current is configurable from 21.0 to 21.6 mA with a factory default setting of 21.0 mA. The 
reaction time after the occurrence of a critical error until the output of the alarm current amounts to 

≤1 min. 

Содержание LLT100

Страница 1: ...LLT SIL FUNCTIONAL SAFET Y GUIDE LLT100 Laser level transmitter...

Страница 2: ...in this document is current and accurate However no guarantee is given or implied that the document is error free or that the information is accurate ABB makes no representations or warranties with re...

Страница 3: ...ilities 15 Systematic integrity 15 Random integrity 15 Safety parameters 15 General requirements 17 4 Installation and commissioning Installation 19 Physical location and placement 19 Electrical conne...

Страница 4: ...Page intentionally left blank...

Страница 5: ...ss of an automatic diagnostic and is not detected by another diagnostic Fail Dangerous Failure that does not respond to a demand from the process i e being unable to go to the defined fail safe state...

Страница 6: ...r HFT Hardware Fault Tolerance Ability of a functional unit hardware to continue to perform a required function when faults or errors are prevailing HMI Human Machine Interface In this case the HMI is...

Страница 7: ...ev D Operating Instruction http new abb com products measurement products level laser level transmitters llt100 AD2 DS_LLT100 EN_Rev C Datasheet http new abb com products measurement products level la...

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Страница 9: ...re and high temperature applications Ordering specifications are described in the LLT100 data sheet AD2 Refer to this data sheet to get exact measuring range operating temperature and accuracy specifi...

Страница 10: ...to date revision in this table Safety Release Number Release Date Software Version FPGA Version Release Notes 1 15 June 2018 1 01 03 1 01 03 Initial safety version Restriction for combination of vesse...

Страница 11: ...0 can be performed directly on its HMI or with HART communication protocol through a computer or handheld terminal The LLT100 connects to the user logic device to control one or multiple actuators for...

Страница 12: ...2 of span 2 of 16 mA The safe state output current can be configured to be 3 6 mA low alarm or 21 0 mA high alarm with the exception of CPU faults where the current output is in low alarm mode 3 6 mA...

Страница 13: ...en 10 s and 20 s due to internal power management constraints If a CPU fault occurs at startup during the instrument self test the current output is in low alarm mode 3 6 mA Power Failure Alarm Behavi...

Страница 14: ...All other instrument configurations can be used for a Safety Instrumented Function Behavior for undetected faults If a LLT100 fault occurs and is not detected through its internal diagnostics the saf...

Страница 15: ...ecific failure rates of all products included in the SIF Each subsystem must be checked to ensure compliance with minimum hardware fault tolerance requirements The safety parameters used for SIL calcu...

Страница 16: ...3 All safety related parameters are calculated using the Exida Electrical and Mechanical Component Reliability Handbooks 4th edition The Exida environmental profile chosen for this FMEDA was Exida Pr...

Страница 17: ...nfirming that the LLT100 nameplate contains the CS label as part of the model identification code An example of such a valid identification code is shown below LLT100 AIAH10L5 E03 CS P901 Personnel pe...

Страница 18: ...18 User Guide...

Страница 19: ...In solid applications if the laser is installed with an angle the setting level calibration points in AD1 shall be executed to calibrate the actual depth of the monitored vessel with the measured dept...

Страница 20: ...ge or configuration of safety parameters the safety function of the device shall be verified see Verify safety function on page 21 After the safety function has been checked device operation must be l...

Страница 21: ...A 1 From the Process Alarm menu select Process Alarm Limits Current Out Low Alarm or High Alarm 2 From there edit the value as necessary based on the information above 3 Press OK Verify safety functio...

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Страница 23: ...be performed by following the steps described below Testing the instrument To check the safety function of the device proceed as follows 1 Verify and record the conditions as they are found prior to c...

Страница 24: ...12 Restart the device by powering it down 13 Check the measured distance or ullage against a secondary standard on an installed device which could be a calibrated reference device a mobile calibration...

Страница 25: ...instrument is taken out of service Replacing modular components by original ABB spare parts is permitted if personnel was trained by ABB for this purpose Before sending the unit to ABB it must be clea...

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Страница 27: ...Chapter 6 Document status Change record Version Date Change Description A 18 June 2018 Initial release...

Страница 28: ...Architecture Constraints must be verified for each application Safety Function The 4 to 20 mA current output will reflect the calibrated range in level volume or ullage as selected by the user within...

Страница 29: ...C001 Certificate Certificat Zertifikat Series LLT100 Lidar Sensors Systematic Capability SC 2 SIL 2 Capable Random Capability Type B Element SIL 2 HFT 0 Route 1H PFH PFDavg and Architecture Constraint...

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Страница 31: ......

Страница 32: ...dify the contents of this document without prior notice With regard to purchase orders the agreed particulars shall prevail ABB does not accept any responsibility whatsoever for potential errors or po...

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