Siemens SITRANS FUS1010 NEMA-4X/ IP 65 manual Arithmetic Operation, Multi-Path Operation

Section 1 1010NFM-3J

1.7.4ESSENTIAL INFORMATION FOR USERS OF MULTI-CHANNEL 1010’s Multi-Channel Meter Type

If your 1010 is a multi-channel model, it offers 2 or 4 independent measurement channels. The meter’s resources are divided among these channels equally. This means that analog Input/Output, relays and digital command lines will be fewer than for single channel machines. We’ll show you later how to “get around” this limitation for times when you need all your multi-path meter’s resources for a single measurement channel.

If one, two or three channels are running when you are trying to setup the last channel, it could take a very long time for the setup; some 10 to 15 minutes should be expected. A great time saver would be to turn each channel off after setup (setup one channel at a time) and reactivate all after everything is setup; then the setup time goes very quickly.

Your datalogger and site storage memory, being bulky resources, are not divided up at all, and remain available for each channel’s use. You will be able to save and recall sites to and from the various channels as long as they share an identical measurement technology (Reflexor, clamp-on, flowtube, etc.). Be aware, however, that moving a site from one channel to another like this, will likely require a new initial installation to achieve its best potential. This is especially true if the new target installation is not on the same pipe or uses another pair of transducers whose nominal characteristics are identical. Note that datalogger reports will be interleaved in memory and their frequency is con- trolled by the interval that was selected for each channel. Providing each site with a unique name will enable you to sort these out when analyzing the data later.

Arithmetic Operation

The dual channel instruments provide a modality of operation which permits the user to arithmetically combine (through addition or subtraction) the results of the two independent measurement channels. Installation of each channel is done via the dual channel menu. Site Saving and Recalling automati- cally recall the contributing sites. While the displays for each physical channel provide you all the data (flow rate, totals, etc.) that are provided via independent channel operation, user Input/Output is largely oriented toward the virtual channel - Channel 3.

Multi-Path Operation

In many cases, the performance of an ultrasonic transit time meter can be improved by allowing it to interrogate the flow field with more than one beam. Imperfect flow profile conditions such as non-axial, cross-flow or an off-center higher-rate flow core, which can cause a single path machine to mis-report the flow rate, are often remedied in this way. The multi-path installation is similar to arithmetic opera- tion; except for the fact that the virtual, or output channel has pipe dimension attributes (which in the arithmetic meter channel it does not). This means that when you install a multi-path meter, pipe data must be installed in Path 1 and Path 2. Your 1010 meter facilitates this by copying pipe data that you installed as Path 1 and Path 2 data to the other paths. It is seldom, if ever, necessary to “trim” the pipe data for the individual path channels - although you may install different size or type transducers for each path. Once you define the pipe, move the menu to the individual paths using Select Path for the physical installation of each channel. This is accomplished in the same way that individual channels are installed.

Save and Restore Operations for multi-path sites execute on all the component chan- nels simultaneously; the individual paths of multi-path sites do not have any existence or autonomy as single channel sites. You will also find that individual path channels possess a reduced set of user- accessible menu functions. For example, although you may zero each individual path, the meter provides Kc control (slope correction) for the virtual channel (system channel) only. You will find that the features and functions provide for each physical channel to focus mainly on the physical measure-

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