Emerson I-0021 Manuel D’Utilisation

NGA 2000

90003482(2) [NGA-e (MLT-Software 3.2.X)] 07/98

Any AM has LON-variable:

• 

PROCESS

This variable is an input-variable. Its meaning is to tell the AM that another instance is not
allowing the measurement sample to flow valid.

In the AM are some states depending from PROCESS.

• 

"valid measurement" only if PROCESS = "valid sample gas".

• 

holding analog outputs if PROCESS = "no valid sample gas"

• 

watching limit violations is switched off if PROCESS = "no valid sample gas"

It's now the task of the system calibration to handle the variable PROCESS for any involved
AM. This is done in the following way:

Any switching of a system valve looks if in the switched valves is a sample valve of any AM.
If yes, then it sets PROCESS like follows.

switched off

-

sample not valid

switched on

purge time of sample valve

sample valid

It's very important to notice following:

SYSCAL only watches state of appropriate sample gas valve for setting of PROCESS-
variable.

Any additional valve, serial to sample valve, which can switch off flow of sample gas can not
be registrated for logic of PROCESS-variable.