KROHNE VFM 5090 EN - Manual (Page 47)

6.2.8 Current (analog) output I
Current output gives an analog representation of the flow rate, power and net power also. Programming of current
output is provided by 1.3.X functions.
Fct. 1.3.1 FUNCTION I current output function
Choose YES to make current output active as per functions Fct. 1.3.2 to Fct. 1.3.4. NO makes current output
inactive (0 mA). When current output function is not required choose the option NO.
Fct. 1.3.2 RANGE I current output range selection
Current output can have a 0-20 mA or 4-20 mA range with or without error indication. Flow rates corresponding
to I
0%
[= 0 mA for 0-20 mA ranges and = 4 mA for 4-20 mA ranges] and I
100%
[= 20 mA for both ranges] are
programmable. Refer to figure I-1 for behaviour of current output.
Fct. 1.3.3 0/4mA FLOW and Fct. 1.3.4 20 mA FLOW
Allows to define relationship of current output with respect to the flow rate.
Refer to figure I-1 and Sect. 6.
Fct. 1.3.5. VARIABLE I Current output selection function
You can have current output proporational to any of flow, power and net power. This facility is available if the
meter is Heat meter or Net Heat meter only.
Since validity of the minimum and maximum values of net heat meter is not checked, please ensure that the value
for 20 mA is greater than that for 4/0 mA by a factor of 2.
Fct. 1.3.6 0/4 mA POWER and Fct. 1.3.7 20 mA POWER
This defines the relationship between current output and power for Heat meter and Net Heat meter. Refer to
figure I-1 and sect. 6.
TESTING OF CURRENT OUTPUT I
Fct. 2.2. TEST I can be used to check current output. The following test values are provided 0/2/4/10/20/22 mA
to be monitored on a current meter. During the test, current output changes to the test value(s). The normal
current value is restored automatically [as per programming of current output] when the testing is over.
CHARACTERISTICS OF CURRENT OUTPUT I
Diagram I-1
6.2.9 Frequency (pulse) output F
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