Elgas DATCOM, Operating Instructions Manual

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7
Technical Description of the Device
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7.3 ELCORplus indexer – Description of mechanical indexer
The mechanical indexer ensures the mechanical transmission of the gas meter rotation to the
shaft with the orifice located in the mechanical indexer. Based on the sensing of the rotation of
this diaphragm, the generation of pulses for the converter is ensured. Shaft rotation, resp. the
aperture is scanned optically by means of light emitting diodes.
The generated pulses are processed and stored in the internal memory of the electronics of the
mechanical indexer and from there they are transmitted by a communication protocol to the S0-
MIE module of the converter for further processing. The setting of the correct direction of rotation
of the indexer counter in accordance with the gas meter is performed during the installation of the
device and is described in paragraph 5.4.3. The mechanical indexer also includes sensitive
external magnetic field sensors that detect an attempt to disrupt its function.
The information transmitted from the mechanical indexer is:
 pulses carrying information on gas consumption and gas flow
 direction of rotation of the gas meter
 signal of an attempt to disturb the function of the indexer by an external magnetic field
The evaluation of the disturbance signal depends on the setting of the device parameters
(parameter TAMPER in the device parameters, see Fig. 56) and can be included in the alarm
signal, resp. cause a call to the dispatcher. Furthermore, this signal can be stored in archives
together with a time stamp, and it can also be included in the status of the device, the resulting
total status of which is shown on the device display (see Tab. Table 11 and section 6.9). It can be
stored in the status archive as an intrusion contact (W7 or W8, see Table 15).
The mechanical indexer is electrically connected to the SLOT 0 terminal block on the I/O board of
the device. The device must have the S0-MIE module in the SLOT 0 position.
SLOT 0
signal
color of
wire
terminal
1 GND white
2 U+ green
3 RxD brown
4 TxD yellow
5 Ub gray
6 TxD ---
Table 16 Connection of mechanical indexer to SLOT 0 terminals
The electrical connection of the mechanical indexer to the SLOT 0 terminals is secured with a
seal. (Elgas security marks).