Elster 83 462 140, Operating Manual And Installation Instructions

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Volume Conversion Device EK260
92 Elster GmbH
4.5 Connecting a meter with encoder
From program version 2.00 onwards the EK260 i s also available in a version which
enables an encoder totalizer to be connected to read the actual gas meter counter reading
and to be used as the input for actual volume.
After each activation by the connected device (e.g. EK260), an encoder totalizer in tegrated
into the gas meter sends the absolute counter reading precisely in the representation as it
is read off the mechanical totalizer, i.e. the "actual meter reading". The connection
between the Volume Conversion Device and the encoder totalizer is made with just two
wires which act simultaneously as the power supply for the encoder and as data lines.
Compared to conventional pulse transmission, this procedure offers a number of
advantages, e.g.:
-
No loss of actual volume due to temporary disturbances.
-
When using a modem on the EK260, the counter reading of the gas meter (actual counter)
can be read remotely.
With the connection of an encoder totalizer, Md.I1 (
→
3.10 ) should be set to "5". A copy of
the cyclically read gas meter counter reading can then be called into the EK260 display as
the actual counter Vo (
→
3.10 ). The reading of the counter and saving as Vo occurs with
the measuring cycle MCyc (
→
3.8), i.e. normally every 20 seconds.
The progress of Vo is used as the input quantity for computing all the actual and volume at
base conditionss (
→
3.2, 3.1).
Also, if with disturbances (e.g. cable breakage or low batteries in the EK260) no data
transmission is possible over a longer time period and so no actual volume can be
acquired, no quantities are lost, because the EK260 immediate ly reads the present gas
meter reading once the disturbance is rectified. However, since no assignment to the
various measured values of pressure and temperature can be made for the period of the
disturbance, these quantities are converted to volume at base conditionss with substitute
values and counted as disturbance quantities.
With a connected encoder no entries can be made for Vm and VmD (
→
3.2). By changing
Md.I1 (
→
3.10) to "0" and then setting it to "5" again, Vm can be set to the gas meter
reading and VmD cleared.
If a connected gas meter with encoder is to be replaced by a new one, Md.I1 (
→
3.10 )
should be set to "0" before making the connection and set to "5" again afterwards. If this is
not carried out, the EK260 does not know that a new meter has been connected and
interprets the change of meter reading incorrectly either as reverse running or as an
increase in volume on the meter:
If the new meter reading is lower (reverse running), the EK260 waits until the reading of
the old gas meter has been reached before it continues to count Vm and Vb.
If the new meter reading is higher, the EK260 sees an increase in volume (not actually
present) which it adds to Vm and, converted, to Vb.
Further information on the interface and the compatibility conditions can be found in the
Internet at the address www.elster-instromet.com.