MSA SUPREMA - Page 57

REV 0, June 2005 Page 57
Operation Manual SUPREMA
4. Operation of the System
message will appear with the warning that the performance test approval of the system will
become invalid.
To guard against typing errors the new password must be entered identically, two times, before
it becomes valid.
Signal if Inhibited
Field type: Selection
If a MAO-module is used to inhibit the sensor signals, there are three different ways of analogue
signal behaviour for inhibited inputs.
• pass: The received measurement values are sent on.
• hold: The last measured value before inhibiting occurred is retained.
• maintain: The signal goes to the maintenance level (corresponds to 3,0 mA).
The requests of EN 50271 concerning the signaling of exta conditions at the analog
outputs is comply only if the function Maintain is setted.
The Setting in this field is essential for all latching measuring points in the whole
system.
OK
Field type: Button
Press this button to accept the settings entered. After the button is pressed, the parameters
are immediately checked to see if they valid. If the parameters are valid, they become part of
the system’s parameter set. If they are not valid, a warning appears.
Cancel
Field type: Button
Press this button to cancel the settings entered.
Maintain
Access to the “Maintain” menu is restricted. Data can be called up and displayed, but changes
and deletions are only possible after entering a password or operating a key switch.
Calibration
To calibrate the individual gas detection inputs a manual or semi-automatic (not yet available)
calibration procedure can be used. After a calibration process has been started using the MDO
operation/display unit, a ‘Zero’ gas must be introduced by maintenance personnel. Then a
‘Test’ (span) gas must be introduced. The results of a calibration are then displayed and are
considered valid thereafter
(see section 7.1 Maintenance and Adjustment).
ICalibration parameters for the individual inputs can be set in the calibration menu. From that
point on the calibration is controlled.
The menu is divided into two submenus:
• “Start calibration”
• “End calibration”
If an input is selected that is not already in calibration mode, the “Start calibration” menu appears.
If an input is selected that is already in calibration mode, the “End calibration” menu appears.