NGA-2000 System Calibration

4.4 Holding analog outputs of the SIO and avoid limit violation alarms

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.

sample gas

time delay

PROCESS-

valve

 

variable

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.

Supplement - 32

NGA 2000

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