KROHNE VFM 1091 - Manual (Page 9)

Part B Signal Converter VFC 091
5. Opening of the signal converter
5.1 General
5.1.1 Starting up signal converter
When power is switched ON to signal converter it displays TEST, VFM, 1091 & Ver.x.x.x and then goes to measurement mode. In this initial
sequence VFM 1091 (I) carries out self-diagnostics to check its own functiona1elements and loads the configuration data from non-volatile
memory. If any error(s) are detected in power on diagnostics converter displays
FATAL . ERROR since instrument has critical error(s) and is not able
to carry normal measurements. The first measured parameter displayed is the one being displayed when power supply was removed last time.
5.1.2 Measurement Mode
In measurement mode, the parameters that converter measures/computes are shown on display in the appropriate units. (See Sect. 5.2 for display
details). As per the configuration, display can be either in non- cyclic/cyclic mode. In non cyclic mode of display, use key to see the next
parameter on display. In cyclic mode display shows all parameters one after another, wherein each parameter is displayed for about 6 seconds.
While in the measurement mode, the flow and the current values can be monitored using the HART
® Communicator. Other than flow and current
values, the communicator also displays the minimum and maximum values of flow values, which are programmed into the device.
5.1.3 Programming or menu mode
All the configuration/settings/test functions are grouped in the form of menu having a tree structure (see Sect. 5.3.1 for details) and are accessible
in the programming mode. Operator can view or alter the present settings, data values by the use of functions available in this mode. VFC091
implements all the universal commands and relevant common practice commands of HART
® this enables you to program some of the main
parameters using HART ® Communicator. These are mainly flow-related parameters.
All changes made in programming mode are stored in non-volatile memory and have appropriate effect on the operation of signal converter. While
being programmed (i.e. while in the menu), the instrument will stop making further measurements and the current O/P will be frozen to the last
value, pulse O/P will also stop. The changes made using the HART
® communicator are stored in the communicator till you request to "Send" the
data to the device. After data is received, VFC091 updates the configuration n with thenewly received data. During the updation period, the
measurement is interrupted. (The updation time is less than half second).
5.1.4 Error handling
Converter can detect errors during power-on diagnostics as well as when in normal measurement mode. Errors are put into two main categories
viz. fatal errors and non-fatal errors. Fatal errors cause measurement to stop since they are serious in nature. Non-fatal errors do not affect
functionality of the converter.
If one or more errors are present, display (in measurement mode) starts blinking. If programmed so, error information is shown on display interleaved
between display of two parameters.
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