The health and status of both SLS 1508 Logic Solvers and their channels are

available in the diagnostics explorer.

When one of a redundant pair of SLS 1508 Logic Solversis removed online there

is no disturbance to the process.

When the missing SLS 1508 Logic Solver is replaced with another SLS 1508 Logic Solver,

the new SLS 1508 Logic Solver completes its power-up self-tests before the

active Logic Solver cross-loads the current database.

In safe areas, failed SLS 1508 Logic Solvers can be replaced under power.

In hazardous areas,appropriate installation procedures must be followed.

Automatic proof testing can be selected on a redundant pairof SLS 1508 Logic Solvers.

The desired proof-test interval is set in the configuration and the SLS 1508 Logic Solvers perform

the proof test automatically. A warning is given to the operator before

the automatic proof test is started.