Service manual

MDS E-SCAN MONITOR OPERATION

PURGE MISSED: This indicates that the steam solenoid relay was not activated

during the purge operation and therefore the purge did not occur.

PURGE INVALID: This indicates that either the steam solenoid relay was activated

during a non-purging operation or there is an open-line condition.

PURGE NOT ACTIVE: This is caused by not having purge cycle times set. This alarm

flashes above the alarm box and does not take the refractometer off

line.

ISO.VALVE:

This status field monitors the Isolation Valve in order to indicate valve open or valve closed

status.

VALVE CLOSED: This indicates that the isolation valve is closed.

5.2.3 Monitor Status Box MDS in Normal Mode

P/SUPPLY:

This status field monitors the Monitor +15 and -15 volt power supply lines. The following errors

can be displayed in this status field:

+15 VOLT ERROR: This indicates that the plus 15 volt supply is outside the allowable

10% tolerance levels which means it is either below +13.5 volts or

above +16.5 volts.

-15 VOLT ERROR: This indicates that the minus 15 volt supply is outside the

allowable 10% tolerance levels which means it is either above

-13.5 volts or below -16.5 volts.

COMPARATOR:

This status field monitors the readings from both MPR E-Scan units and is used to indicate an

error if the difference in the solids readings exceeds the comparator limit. The operator has the

capability of changing the comparator limit to a value between 1% and 2% absolute solids by

using the Monitor Configuration Limits menu option.

COMPARATOR ERROR: The difference in solids readings exceeds the comparator limit.