Functional Safety 2016

November, 2016 - London

Page 11 of 17

Equipment

Proof Test Method (brief description)

(%)

from the pressure actually present. If the display value and digital value are also to

be corrected, please contact MANUFACTURER

6. Restore the complete operativeness of the current loop.

7. Disable safety PLC bypassing or restore normal operation in

some other way.

8. Once the recurrent test has been carried out, the results must

be documented and stored in a suitable manner.

Logic Solver

Checking the channels of input/output modules

•

Change the input value or output value of each channel of the

modules and check if the modules work as intended.

For dual-reducndant modules, check on both modules.

Control right switch over (for Redundant CPU Modules and Input/

Output Modules)

To ensure high availability, use the following procedures to check

that switchover takes place properly on dual-redundant modules.

CPU Modules

1. To make a switch over, press the START/STOP switch in the

front of the control-side CPU module to stop it.

2. Press the START/STOP switch of the failed module once

again to restart it. The module should start up as a standby-

side.

Input/Output Modules

Use the IOM Control Right Switching Tool to make switchover on

AIO/DIO modules. This tool switches the control right of dual-

redundant AIO/DIO modules from the SENG.

By using this tool, the control right will be switched over to the

modules on the standby-side.

However, you cannot use this tool on dual-redundant serial

communication modules (ALR111, ALR121).

You can start the IOM Control Right Switching Tool from Explorer.

Switch over can be made either for a selected pair of AIO/DIO

modules or collectively on a node-by-node basis.

~95%

Solenoid

Valves

1. Bypass the safety PLC or take other appropriate actions to

avoid a false trip, following company Management of Change

(MOC) procedures.

~99%