RMG ERZ2000-NG, Operating Manual

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6 Flow meters
Manual ERZ 2000-NG · EN07 · 2019, May 13th
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6.4 Connection of USZs via Instance F
There has been a desire for some time to standardize the connection of ultrasonic
meters to further electronic evaluation units. In particular, the desire arose to
transmit "all" data determined by an ultrasonic meter, i.e. measurements and
status information or diagnostic data, in the same manner. Recently, the connection
via Instance F crystallized as a standard.
6.4.1 Explanation of the term Instance F
Ultrasonic meters normally do not have dedicated DSfG bus access. Therefore, In-
stance F was implemented externally via a DSfG-compatible flow rate computer. The
data required for this is transmitted via Modbus between ultrasonic meters and flow
rate computers. This Modbus protocol is frequently already called Instance F, alt-
hough it is only prepared for the data required for the DSfG Instance F. In the
ERZ2000-NG , the appropriate settings are found in menu VK Modbus master USM .
The corresponding register plots are provided in menu VJ Register expressions .
Figure 161: Data exchange between ERZ2000-NG and USM GT400