S0 pulse counter with SNMP and Modbus/TCP

This Case study is about connecting S0 pulse outputs of the meters (Electricity, Gas, Water) to the Ethernet and reading values over the Open API (SNMP, XML, Modbus/TCP or MQTT protocols).

Pulse outputs from 3rd party meters (S0 interface) are connected to the DI (Digital Input) of the Poseidon2 / Damocles2 Ethernet I/O unit. Each DI (Digital Input) on the supports a 32-bit pulse counter. The counted value is shown on the device web interface and is available on Open API over LAN.
Second Portal option to analyze pulse counters include even other HWg devices with GSM / LTE / NB-IoT connectivity. Counter data are analyzed in the analyze the data in the Portal - Graphs, Reports, Alerts and other portal tools. The SensDesk Technology based portals supports Open API interface to other systems per each user account (XML, SNMP).

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Solutions

Issue description:

Many standard 3rd party meters of Electricity, Gas or Water supports pulse output (S0 standard). This pulse output can be easily connected to the Damocles2 device (DI - Digital Input) or other HWg devices.

LAN devices: The pulse counter value is available for reading via Open API protocols of the Damocles2 / Poseidon2 LAN device.
GSM/LTE & NB-IoT connected devices: Devices have to be connected to the SensDesk Technology based portal. Above graphs, alerts and reports provides each user account on SensDesk.com (and other portals) Open API per user account. Use XML or SNMP for reading pulse counters.

Applications

Electricity consumption monitoring for datacenters (reading S0 pulse output electricity meters)
Energy consumption monitoring on the Portal (SensDesk Technology)
Digital pulse counter (32 bits) on some HWg products
- S0 to SNMP conversion
- S0 to Modbus/TCP conversion (popular for SCADA)
- S0 to MQTT protocol conversion

Solutions	Benefits	Solution image
Data center energy monitoring S0 power consumption monitoring (1/3 phases) Gas / Water consumption monitoring Can be connected to SCADA system	Any 3rd party meter with S0 pulse output can be used S0 output is common for Electricity / Gas / Water meters Portal is able to show graphs and convert pulses to [kWh] / [m3] / [l] HWg Software PDMS converts pulses to [kWh] / [m3] / [l] LAN / LTE / NB-IoT devices with DI pulse counter inputs are available

Technical description

The 3rd party energy meter must have an S0 pulse output.
The S0 output is connected to a DI (Digital Input) of some HWg devices
DI pulse counters are available on
- 4x DI - Damocles2 MINI
- 12x DI - Damocles2 1208
- 24x DI - Damocles2 2404
- 4x DI - Poseidon2 3266
- 4x DI - Poseidon2 3268
- 4x DI - Poseidon2 3468
- 12x DI - Poseidon2 4002
- 2x DI - Ares 12
- 2x DI - SD-2xIn
- 2x DI - NB-2xIn
The number of S0 pulses is directly proportional to the amount of consumed energy (e.g. 1000 pulses = 1 kWh).
- This ratio is specific for the particular 3rd party energy meter.
- This ratio has to be recalculated in a higher (SCADA / Portal) system.
Pulse counter value for each DI is available on the web interface (Damocles2, Poseidon2, Ares) unit.
The value of Pulse counters are all the time increasing only.
Pulse counter values in the Damocles2 device are protected against power failure (Non-volatile counter memory - counter value is stored even during device power off).
Each one pulse must be longer than 20 ms to be registered by counter.
HWg devices are compatible with S0 output of the meters. The DI input current can be lower than S0 required 2mA (check in device specifications).
How to reset pulse counters?
- Resetting the Damocles2 / Poseidon2 device configuration (load defaults) also resets all counter values to 0.
- On the General Setup (web) page (device web) you can also reset all counters.
- IoT Monitoring devices do not support reseting pulse counters on the device level. You can "reset" value by the Calibration (shift) per each Digiat Input on the Portal.
Pulse counters for each Damocles2 DI are available over the LAN through the following protocols:
- SNMP
- XML (over HTTP)
- Modbus/TCP
- MQTT
The counter values can be shown in the SensDesk Technology portal (it has to be enabled per Damocles2 device).
- Portal can show graphs & provide alerting based on consumption
- Portal can analyze water consumption minimum-level overnight by using virtual sensors
- Even LTE or NB-IoT connected devices with Pulse counters can be connected to the portal
- Portal Open API: SNMP, XML (per user account)
The counters can be analyzed in the HWg-PDMS software.
- In PDMS, pulses can be converted to energy (for example 1000 pulses = 1kWh)
- PDMS can correctly handle device restarts and counter resets
- PDMS can export energy consumption to MS Excel as a list of 5 or 15 minute differences

Damocles2 WEB interface for DI counters

Portal (SensDesk Technology):

Graph of the S0 counter

Counters have to be activated in the device settings

Open API (Device)

XML format of the S0 pulse counter

SNMP output of the S0 pulse counter

What is the S0 pulse interface?

The S0 interface is a hardware interface for the transmission of pulses, the definition of the interface is described in standard EN62053-31.
The S0 output of 3rd party meters is designed as a switch, often a mechanical switch or open collector. S0 output has two states ON/OFF. The number of pulses is proportional to the measured value.
The statuses ON/OFF are defined via the current because the voltage can be variable. Voltage is provided by DI (Digital Input) from the Damocles2 device.
The S0 duration of a pulse is at least 30 ms (ON/OFF state)
The S0 interface is divided into two classes:
- S0 class A for long distances (Max 27V DC, Max current for ON=27 mA, Min current for ON=10 mA, Max current for OFF=2.00 mA)
- S0 class B for short distances (Max 15V DC, Max current for ON=15 mA, Min current for ON=2 mA, Max current for OFF=0.15 mA)

Devices

Standalone Monitoring

Ares 12 LTE

Damocles2 1208

Damocles2 MINI

Damocles2 2404

IoT Monitoring

NB-2xIn

SD-2xIn