CIRCUTOR DHB Series - Manual (Page 54)

54
9. PROGRAMMING EXAMPLES
Example 1. Programming the meter to work with the flowmeter with reed
relay output of the following parameters:
- pulse constant 1K - 4,3956 dm
3 /pulse = 0,0043956 m 3 /pulse;
- minimal flow Q
min
– 0,02 m 3 /h
The parameters of input 1 should be set as follows:
-
tYP1 should be set to FreqL (frequency for (f<10kHz));
The pulse constant for scaling should be given in m 3 , but only five
significant digits can be set. When multiplying by a constant ( SCAL set
to AND), when rounded to five digits we get value 0.0044 (introducing to
the result of the calculation error of 0.1%). To reduce the error introdu-
ced by the conversion, change the scaling by a constant dividing (
SCAL
set to div) and as a constant value write the multiplicative inverse:
ConS1= =227,5002275 ≈ 227,50
When the inverse is rounded to five digits, the error introduced into the
calculations is of the size of 0.0001%.
-
SCAL1 should be set to dIv, ConS1 should be set to 227,50;
- t_L1 and t_H1 should be set to a value 10 [ms] (due to the multiplication
of the pulse with a mechanical switch);
-
E-In1 – if no control inputs are used, should be set to bUt;
To set the time, after which a zero flow will be indicated, the maximum time
interval between pulses should be calculated for minimum flow Q
min
.
maximal time interval between pulses t_
max
=
t_
max
=
1
0,0043956
pulse weight [m 3 ] * 3600 [s]
Q
min
[m 3 ]
0,0043956 * 3600 [s]
6