Maintenance/Check; Overview - Siemens SITRANS P DS III Operating Instructions Manual

● Fault rates are calculated on the basis of a mean time to repair (MTTR) of eight hours
(order option C21).
● Only one SITRANS P DS III device is required for single-channel operation in accordance
with SIL 2.
● Secure data transmission is only guaranteed when using a PROFIsafe master.
8.5

Maintenance/check

8.5.1

Overview

Checking safety
Check the safety function of the entire safety circuit on a regular basis in accordance with
IEC 61508/61511. The test intervals are determined in the course of calculations for each
safety circuit of a system (PFD
Checking safety function/proof test
Runs this test to detect hidden serious faults of the pressure transmitter.
Hidden faults result in incorrect measurements and dangerous failures in your safety-related
system.
If necessary, replace the pressure transmitter.
Enabling write protection
After parameter assignment/commissioning as well as after a proof test, perform the
following steps:
1. Disable the write protection. For this purpose you have various options, which are
described in the section "Write protection (Page 150)".
2. Protect the keys from unintended change in the parameters, e.g. by selecting the key lock
or function lock (Mode 10).
Electronics and measuring cell
The safety function of the pressure transmitter is ensured only if you use the electronics,
measuring cell, display and connection board delivered by the factory. These components
cannot be replaced.
SITRANS P DS III/P410 with PROFIBUS PA
Operating Instructions, 02/2016, A5E00053276-08
).
AVG
Functional safety
8.5 Maintenance/check
133