VEGA VEGAMET 391 With SIL qualification User Manual

Page 16

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6 Functional safety (SIL)

VEGAMET 391 • With SIL qualification

38704-EN-130228

4 … 20 mA sensor input with transmitter power supply

Relay outputs 3/4

4 … 20 mA current output

Note:

The following inputs/outputs are not permitted for safety-relevant

applications:

Digital input 1/2

Relay output 1/2

Measured value transmission via the communication interfaces

(USB/HART)

6.4 Safety concept of the parameterization

The following tools are permitted for parameterization of the safety

function:

The integrated display and adjustment unit for on-site adjustment

The DTM suitable for the signal conditioning instrument in con-

junction with an adjustment software according to the FDT/DTM

standard, e. g. PACTware

Note:

For operation of the VEGAMET 391 mit SIL-Qualifikation the DTM

Collection 06/2011 or higher is required. The modification of safety-

relevant parameters is only possible with active connection to the

instrument (online mode).

To avoid possible errors during parameterization in a non-safe user

environment, a verification procedure is used that makes it possible

to detect parameterization errors reliably. For this, safety-relevant

parameters must be verified before they are stored in the device. In

normal operating condition, the instrument is also locked against

parameter changes through unauthorized access. This concept is

valid for adjustment directly on the instrument as well as for PACTware

with DTM.

All safety-relevant parameters must be verified after a change and

confirmed by a character string comparison. The following parameters

of the relays 3/4 are judged as safety-relevant:

Mode relay output

Relay switching point Hi

Relay switching point Lo

The parameter settings of the measurement loop must be document-

ed. For this purpose, the document "SIL device settings" is attached

to each instrument already listing all safety-relevant parameters in

the shipping status as well as containing free space for own notes.

This document is also available via the serial number search on our

homepage. In addition, a list of the safety-relevant parameters can be

stored and printed via PACTware/DTM.

Tool for operation and

parameterization

Reliable parameterization

Safety-relevant param-

eters

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