CMi-6160 NB-IoT Module for Sharky 775

An Overview of the CMi-6160

The CMi-6160 is an integrated meter connectivity module (MCM) that mounts inside a Diehl Sharky 775 heating/cooling meter to deliver meter data via a Narrowband IoT (NB-IoT) network. It is manufactured by Elvaco AB and is ideal for applications where long range is required. The module can be battery operated for up to 13 years with daily data transmission, or mains-powered if preferred. Meter data delivery and device management use standard protocols including MQTT-SN and LwM2M for easy integration with existing systems.

• Compatible with Diehl Sharky 775 (minimum firmware FW02)
• NB-IoT connectivity — ideal for long-range applications
• Battery operated for up to 13 years, or mains-powered
• Mounts in meter slot 1 of the Sharky 775
• Configured via NFC using the Elvaco OTC app (Android and iOS)
• Can also be activated via push button on the unit
• Supports automatic activation when water flow is detected
• Multiple message formats including Transparent mode
• Meter Alarm Monitor for push alerts from the field
• MQTT-SN and LwM2M data transmission protocols
• One-Touch Commissioning (OTC) via Elvaco OTC app
• Nano SIM card slot
• Internal or external antenna (MCX connector)

Part Codes

Before You Begin

Before installing the CMi-6160 module, ensure the following are in place:

• Diehl Sharky 775 heat meter installed and running firmware FW02 or later
• A Nano SIM card provisioned for NB-IoT on your chosen network
• Access to a receiving system compatible with MQTT-SN or LwM2M
• A smartphone with NFC enabled and the Elvaco OTC app installed (Android and iOS)
• ESD protective measures observed — the CMi-6160 is an electrostatic-sensitive device
• All instructions and technical specifications in this manual read and understood before installation

Installation

Step 1 — Insert the SIM card

Before mounting the module into the meter, insert a Nano SIM card into the SIM card holder on the module. Slide the SIM card into position until it is secure.

Step 2 — Open the meter

Open the Sharky 775 meter by folding down the side latches to access the module slots.

Step 3 — Connect the meter interface cable

Connect the white meter interface cable by attaching it to the meter.

Step 4 — Mount the module

Push the CMi-6160 module into meter slot 1. The guiding pins will help align it into the correct position. Note: the module must be fitted in slot 1 to allow correct alignment of the NFC antenna.

Step 5 — Connect the NFC antenna

Connect the orange NFC antenna to the module. Remove the protective film from the adhesive on the back of the antenna. Press the larger part into position first, then press the thin part of the antenna into place.

Step 6 — Connect the meter interface cable to the module

Connect the white meter interface cable to the module (green connector).

Step 7 — Connect the antenna

Internal antenna: Place the antenna in the meter housing and connect the antenna cable to the MCX antenna connector on the module. Take care not to clamp the antenna cable when closing the lid.

External antenna: Make a hole in the rubber grommet/sealing and push the MCX connector through, ensuring the thicker part of the antenna cable sits in the grommet. Connect the antenna cable to the MCX connector on the module. Ensure the antenna is mounted at least 0.5 metres away from areas where people are permanently present.

Step 8 — Connect the battery

If the battery pack is not already assembled to the meter, follow Diehl Metering's mounting instructions for external battery packs. Once the battery pack is in position, connect the power cable from the battery to the power connector on the CMi-6160.

Device Configuration

Before activating the module, apply the correct configuration profile using the Elvaco OTC app via NFC. Having the meter closed with the display facing you, the NFC antenna is located in the upper left corner of the meter.

The following key parameters should be configured:

• Power mode: Set to Active for standard activation, or Standby to use the automatic activation at flow feature.
• Meter Report Interval: How often the module reads and stores values from the meter (in minutes). A shorter interval gives higher data granularity.
• Meter Transmit Interval: How often the module sends data to the receiving system (in minutes). For battery-operated devices, set a larger transmit interval than the report interval to preserve battery life.
• Measurement mode: Module-controlled (sends preset data per the selected message format) or meter-controlled (transparently forwards the customer-defined telegram from the meter without modification).
• Message format: Multiple formats are available including Standard, Compact, JSON, and Transparent. Refer to the CMi-6160 user manual for full payload details.
• Report data encoding: Select the encoding that best suits your receiving system.
• UTC offset: Set the UTC offset to ensure timestamped meter data is transmitted in UTC. For example, a meter in the UK (GMT) should use UTC offset 0; during standard time this ensures timestamps align correctly.
• Randomized transmission delay: Configurable delay to prevent large populations of devices transmitting simultaneously.
• Configuration lock: When enabled, a device-specific Product Access Key (PAK) is required to access the module, preventing unauthorised configuration changes.

Once all parameters are set, place the phone next to the upper left corner of the meter and tap Apply settings. Hold the phone still until it vibrates three times — this confirms settings have been transferred successfully via NFC.

Activation

Upon delivery, the CMi-6160 is set to inactive mode and will not transmit any messages until activated. There are three ways to activate the module:

Option 1 — Automatic activation at flow

1. Using the Elvaco OTC app, ensure the module is configured with Power mode set to Standby and Automatic activation at flow enabled.
2. Once the meter detects sufficient water flow (defined as permanent water flow for 3 hours), the module will activate automatically and begin transmitting meter data. The module checks for sufficient flow once every hour.

Option 2 — Push button activation

1. Press and hold the push button on the module for at least five seconds.
2. Release the button when the green LED lights up.
3. Wait up to 10 seconds. The module indicates start-up by flashing red and green LEDs for one second.

Option 3 — Elvaco OTC app activation

1. Open the Elvaco OTC app (available for Android and iOS) and ensure NFC is enabled on your phone.
2. Scan the module.
3. Go to Apply mode and set the Power mode to Active.
4. Tap Apply settings and scan the module to apply the new settings.
5. To verify activation, go to Inspect, scan the module, and confirm Power mode is set to Active.

LED status during network connection

• Green and red LEDs lit for 1 second — connecting to NB-IoT network
• Short flashes on green LED — attempting to join the network
• Green LED lit for 8 seconds — network connection successful

If the module fails to connect, it will retry automatically. The interval between attempts increases with each retry until it reaches once per day. A new connection attempt can be started manually by rebooting the module: press and hold the push button for 5–15 seconds and release when the green LED is lit, or deactivate and reactivate the module using the Elvaco OTC app.

Data Transmission

Meter data can be transmitted using either MQTT-SN or LwM2M Send. The two protocols cannot be used simultaneously but can be switched via the Elvaco OTC app or a device management system.

• MQTT-SN: Meter data messages are published to a configurable MQTT-SN topic.
• LwM2M Send: Data is published to LwM2M object 33911.

Upon successful network connection, an initial meter readout is automatically sent to the receiving system. Subsequent transmissions follow the configured Meter Transmit Interval. If unsent meter data is available in the module, it will be transmitted according to the configured recovery strategy.