MOUSER ANR001 METIS-II Wireless M-Bus Modules Owner’s Manual

ANR001 – METIS-II / 260702118301X
REPEATER MODE

Revision history

Introduction

Starting with firmware version 2.8.0 the Metis-II includes a feature to enable receiving, buffering, delaying, and forwarding radio frames better known as a single-hop unidirectional repeater functionality.

Firmware 2.7.0
260702118301x| AMB8626-M-RP-TR| 868 MHz wM-BUS module 14dBm, T&R, Firmware 2.8.0
260702118301x| AMB8626-M-RP-DEV| The development kit, 3 modules Metis-Il with Firmware 2.8.0

Table 1:Metis-II Ordering information

The European Standard EN13757 and the OMS Group Specification give information on how a single-hop unidirectional repeater shall be implemented and what radio frames shall be supported by the repeater. Our implementation will enable the repeater mode only on a very specific configuration set of the wM-Bus module as introduced later.

Using the repeater mode requires the careful attention of the user regarding local regulatory requirements. Especially the duty cycle requirements need to be adhered to. For example by realizing a suiting host implementation in the user’s end system that implements duty cycle restriction.

Motivation

By means of the repeater mode, a module or USB stick can be utilized to enhance the effective radio range of wireless M-BUS meters within the repeater’s range. This will happen for frames that follow EN13757-3:2013 and EN13757-4:2013 as well as OMS Specification Volume 2 Generation 4 V4.1.2. In essence, this applies to all wM-BUS frames that have a hop counter field at a location described in the standard and also have a C-Field of either SND-NR or SND-IR, which are only to be used in direction meter to other (uplink).
As the size of the hop counter field is limited to 1 bit it is not possible to provide multiple hops in a standard-compliant way. Therefore the hop counter must be ’0’ in the received frame and will be set to ’1’ by the repeater to indicate that the message was repeated. A-frame already having the hop counter ’1’ when being received by a repeater will be discarded.
To be able to find the hop counter inside a frame the repeater parses and checks parts of the radio frame upon reception. Currently, the following frame structures and  conditions are implemented in the firmware, listed in the order of priority they will be tested and applied:
Frames that have an Extended Link Layer (ELL) as first Control Information Field (field). This ELL has a Communication Control Field (CC-Field) which provides a Hop
Count Subfield (H-Field). The first Ci-Field can be followed by one or multiple further Ci-Field(s).
Frames that have exactly one Ci-Field in the entire frame, indicating either a “short data header” or a “long data header”, with encryption modes in the Configuration Field
being either 0 or 5 and the Configuration field providing a hop counter at a well-known location within the field.
Note: Encryption mode 0 is not described in the standard but from our experience with different manufacturers mode 0 is used by them with the same structure as mode 5.
This means the Configuration Field Bit 0 is the Hop Counter Field.

Using the included wireless M-BUS repeater

The repeater mode runs in parallel to the normal module functions as sending and receiving frames without interfering with the normal operations of the module or the reachability of the module via UART. To archive this, the frames to be repeated are queued in a non-shared buffer so the normally shared buffer is not blocked by the repeater.
The repeater mode is enabled by setting the UserSetting (US) parameter Enable at index 82 (0x52) from 0x00 (= disabled) to 0x01 (= enabled) via the CMD SETREQ as shown
below is the example configuration in chapter 3.1.
But even though this enables the repeater mode of the module there are further configurations required for the activation to take effect.

Please refer to the wM-Bus module reference manual or the following example section on how to use CMD SET  and CMD GET REQ commands accordingly.
If any of the parameters or requirements are not fulfilled the unidirectional repeater functionality may cause critical malfunctions of the module.
The following table shows the user setting parameters to configure the module as a repeater:

Table 2:UserSettings Requirements

An additional requirement is that no frame preloading shall be used when the repeater mode is enabled. If the preloading is or was used since the latest restart of the module the user is required to use the CMA DATA CLR PRELOAD REQ command OXFF 31 CE in order to clear the preloaded frame from the queue.

Preloading is obsolete since firmware version 2.8.0 and shall not be used anymore.
The command CMD SET MODE REQ shall never be used when the repeater mode is active. Doing so will disable the repeater function.

Configuration using CMD_SET_REQ
By using the following CMD SET REQsequence followed by a CMD RESET REQ the settings to enable the repeater mode will be applied to the non-volatile memory of the module.

Because of the nature of the firmware design radio packets have the highest priority in the shared buffer. Please perform such setting sequences only in non radio polluted environments or by using the ACC PC Software.
You are encouraged to check the currently configured values by using CMD_GET_REQ before using a CMD_SET_REQ to avoid unnecessary flash erase/write cycles as this resource is limited by the hardware.
First, check the firmware version of the module by executing CMD_GET_FWVERSION_REQ (OxFF OC 00 F3). If the response indicates firmware version 2.8.0 (0x02 08 00) or higher you are good to proceed. If you still have an old firmware version use ACC to update to the most recent firmware before proceeding.
Revert to factory defaults
CMD_FACTORYRESET_REQ: OxFF 11 00 EE All UserSettings are reverted to factory defaults.
Restart module to apply factory defaults
CMD_RESET_REQ: OxFF 05 00 FA The Factory defaults are loaded into RuntimeSettings, the UART is now using 9600 baud 8n1.

Please adjust the UART baud rate of your host to 9600 baud after the reset to be able to still communicate with the module.
Set the UART speed to 115200 baud 8n1 CMD_SETUARTSPEED_REQ: OxFF 10 01 07 E9 All UART speed-related UserSettings are updated by this command accordingly. Factory default: 9600 baud 8n1
Revert to factory defaults CMD_RESET_REQ: OxFF 05 00 FA The UART baud rate is now using 115200 baud 8n1.

Please adjust the UART baud rate of your host to 115200 baud after the reset to be able to still communicate with the module.

Set the Mode_Preselect to either S2 or C2_T2_Other
For using S2 mode a reconfiguration is not required. For C2_T2_Other mode use CMD_SET_REQ : OxFF 09 03 46 01 09 BB Factory default: S2 mode
Enable Command Output mode
CMD_SET_REQ: OxFF 09 03 05 01 01 FO Factory default: disabled
Your host needs to implement the Command Interface as specified in the wM-BUS manual plus the additional command CMD_RP_DATA_IND defined in chapter 4 in this document.
Enable repeater mode
CMD_SET_REQ: OxFF 09 03 52 01 01 AT Factory default: disabled
Reset module
CMD_RESET_REQ: OxFF 05 00 FA This will reset the module and activate the settings done above.

3.2 Supported wireless M-BUS modes for the repeater
The single-hop unidirectional repeater requires to receive radio frames. For example, all we-BUS modes containing a “1” are send-only modes and can therefore not be used when the repeater mode shall be enabled. Thus we limited the wM-BUS modes to the following set to provide the functionality of the repeater mode.
• S2 mode, Mode_Preselect value 0x03
• T2-Other mode, Mode_Preselect value 0x08
• C2-T2-Other mode, Mode_Preselect value 0x09
• C2-Other mode, Mode_Preselect value OxOE
By using these modes the repeater receives as if it would be a data collector or Smart Meter Gateway and repeats the frames as if it would be a meter so that the repeated frames (with hop counter changed to ‘1’) can be received by other data collectors and Smart Meter Gateways.
3.3 Energy consumption
By its very nature, the repeater has the radio receive mode activated permanently when not sending a frame. In regard to a battery-operated device, this means that the battery will be drained quite fast. The typical RX current is around 30 mm and the typical TX current is around 53 mA. Therefore the recommendation for a repeater is to be used in mains-powered devices and products only.

4 CMD_RP_DATA_IND
This UART frame will indicate to the host that a frame was successfully repeated.
4.1 Example 1 The indication will share further parameters that can be used by the host system to trace the utilization of the buffers as well as to trace the duty cycle used by the repeater mode. The 1-byte buffer ID is an unsigned buffer index number indicating which internal buffer of the module the repeated frame was using. The 2-byte parameter duration states the TX duration in milliseconds of the repeated frame which successful transmission is indicated by this indication message. The module calculates this value depending on the wireless M-BUS mode, radio frame length, and frame format used to repeat this frame. CS is as usual in the command mode the XOR concatenation of all preceding bytes starting with the start signal OxFF.

Duty cycle requirements

Citation from ETSI EN 300 220-1 V3.1.1 (Feb 2017) chapter 5.4.1, which is required to conform to the RED and CE, at the time this Application Note was written:
Duty cycle is the ratio expressed as a percentage, of the cumulative duration of transmissions To„ ew. within an observation interval Toby. DC = (ToY-7n) on an observation lobs F., bandwidth Fobs. Unless otherwise specified, Lb, is 1 hour and the observation bandwidth F„ bs is the operational frequency band. Each transmission consists of an RF emission or sequence of RF emissions separated by intervals <T.DIS

The manufacturer of the end product has sole and ultimate responsibility for the conformity of the end product to the applicable directives, whether he designed and manufactured the product himself or is considered as a manufacturer because the product is placed on the market “under his name”.
The following table shows the duty cycle for the frequency bands supported by our 868 MHz wireless M-BUS modules. The wireless M-BUS standard does specify the channel access to be random. But it does not specify to implement any channel access methods and due to timing parameters, this would cause EN13757 compliance problems. Thus polite spectrum access (PSA) of the RED cannot be applied to increase the duty cycle. For the repeater functionality, only the role “meter to other” is used for TX operations.

Table 3:Duty cycle as required by ETSI EN 300 200-2 V3.1.1 for all we-BUS modes in 868 MHz Bands

Important notes

The following conditions apply to all goods within the wireless connectivity product range of Wirth Elektronik eiSos GmbH & Co. KG:
6.1 General customer responsibility
Some goods within the product range of Worth Elektronik eiSos GmbH & Co. KG contain statements regarding general suitability for certain application areas. These statements about suitability are based on our knowledge and experience of typical requirements concerning the areas, serve as general guidance and cannot be estimated as binding statements about the suitability for a customer application. The responsibility for the applicability and use in a particular customer design is always solely within the authority of the customer. Due to this fact, it is up to the customer to evaluate, where appropriate to investigate and to decide whether the device with the specific product characteristics described in the product specification is valid and suitable for the respective customer application or not. Accordingly, the customer is cautioned to verify that the documentation is current before placing orders.
6.2 Customer responsibility related to specific, in particular, safety- relevant applications
It has to be clearly pointed out that the possibility of a malfunction of electronic components or failure before the end of the usual lifetime cannot be completely eliminated in the current state of the art, even if the products are operated within the range of the specifications. The same statement is valid for all software source code and firmware parts contained in or used with or for products in the wireless connectivity and sensor product range of Wirth Elektronik eiSos GmbH & Co. KG. In certain customer applications requiring a high level of safety and especially in customer applications in which the malfunction or failure of an electronic component could endanger human life or health, it must be ensured by most advanced technological aid of suitable design of the customer application that no injury or damage is caused to third parties in the event of malfunction or failure of an electronic component.
6.3 Best Care and Attention
Any product-specific datasheets, manuals, application notes. PCN’s, warnings, and cautions must be strictly observed in the most recent versions and match to the product’s firmware revisions. These documents can be downloaded from the product-specific sections on the wireless connectivity homepage.
6.4 Customer support for product specifications
Some products within the product range may contain substances that are subject to restrictions in certain jurisdictions in order to serve specific technical requirements. Necessary information is available on request. In this case, the field sales engineer or the internal sales person in charge should be contacted who will be happy to support in this matter.

6.5 Product improvements
Due to constant product improvement, product specifications may change from time to time. As a standard reporting procedure of the Product Change Notification (PCN) according to the JEDEC-Standard, we inform about major changes. In case of further queries regarding the PCN, the field sales engineer, the internal salesperson or the technical support team in charge should be contacted. The basic responsibility of the customer as per sections 6.1 and 6.2 remains unaffected. All wireless connectivity module driver software -wireless connectivity SDK- and its source codes, as well as all PC software tools, are not subject to the Product Change Notification information process.
6.6 Product life cycle
Due to technical progress and economical evaluation, we also reserve the right to discontinue production and delivery of products. As a standard reporting procedure of the Product Termination Notification (PTN) according to the JEDEC-Standard, we will inform at an early stage about inevitable product discontinuance. According to this, we cannot ensure that all products within our product range will always be available. Therefore, it needs to be verified with the field sales engineer or the internal sales person in charge about the current product availability expectancy before or when the product for application design-in disposal is considered. The approach named above does not apply in the case of individual agreements deviating from the foregoing for customer-specific products.
6.7 Property rights
All the rights for contractual products produced by Worth Elektronik eiSos GmbH & Co. KG on the basis of ideas, development contracts as well as models or templates that are subject to copyright, patent or commercial protection supplied to the customer will remain with WOnh Elektronik eiSos GmbH & Co. KG. WOrth Elektronik eiSos GmbH & Co. KG does not warrant or represent that any license, either expressed or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right relating to any combination, application, or process in which Mirth Elektronik eiSos GmbH & Co. KG components or services are used.
6.8 General terms and conditions
Unless otherwise agreed in individual contracts, all orders are subject to the current version of the ‘General Terms and Conditions of WOrlh Elektronik eiSos Group’. The last version is available at www.we-onllne.com.

 Legal notice

7.1 Exclusion of liability
Mirth Elektronik eiSos GmbH & Co. KG considers the information in this document to be correct at the time of publication. However, Worth Elektronik eiSos GmbH & Co. KG reserves the right to modify the information such as technical specifications or functions of its products or discontinue the production of these products or the support of one of these products without any whiten announcement or notification to customers. The customer must make sure that the information used corresponds to the latest published information. Wirth Elektronik eiSos GmbH & Co. KG does not assume any liability for the use of its products. Wirth Elektronik eiSos GmbH & Co. KG does not grant licenses for its patent rights or for any other of its intellectual property rights or third-party rights.
Notwithstanding anything above, Wirth Elektronik eiSos GmbH & Co. KG makes no representations and/or warranties of any kind for the provided information related to their accuracy, correctness completeness. usage of the products and/or usability for customer applications. Information published by Mirth Elektronik eiSos GmbH & Co. KG regarding third-party products or services does not constitute a license to use such products or services or a warranty or endorsement thereof.
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The customer bears the responsibility for the compliance of systems or units, in which Wirth Elektronik eiSos GmbH & Co. KG products are integrated, with applicable legal regulations. Customer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory, and safety- related requirements concerning its products, and any use of Worth Elektronik eiSos GmbH & Co. KG components in its applications, notwithstanding any applications-related information or support that may be provided by Worth Elektronik eiSos GmbH & Co. KG. The Customer represents and agrees that it has all the necessary expertise to create and implement safeguards that anticipate dangerous consequences of failures, monitor failures, and their consequences lessen the likelihood of failures that might cause harm, and take appropriate remedial actions. The customer will fully indemnify Worth Elektronik eiSos GmbH & Co. KGand its representatives against any damages arising out of the use of any Worth Elektronik eiSos GmbH & Co. KG components in safety-critical applications.
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AMBER wireless is a registered trademark of Worth Elektronik eiSos GmbH & Co. KG. All other trademarks, registered trademarks, and product names are the exclusive property of the respective owners.
7.4 Usage restriction
Mirth Elektronik eiSos GmbH & Co. KG products have been designed and developed for usage in general electronic equipment only. This product is not authorized for use in equipment where a higher safety standard and reliability standard is especially required or where a failure of the product is reasonably expected to cause severe personal injury or death unless the parties have executed an agreement specifically governing such use. Moreover, Würth Elektronik eiSos GmbH & Co. KG products are neither designed nor intended for use in areas such as military, aerospace, aviation, nuclear control, submarine, transportation (automotive control, train control, ship control), transportation signal, disaster prevention, medical, public information network, etc. Würth Elektronik eiSos GmbH & Co. KG must be informed about the intent of such usage before the design-in stage. In addition, sufficient reliability evaluation checks for safety must be performed on every electronic component, which is used in electrical circuits that require high safety and reliability function or performance. By using Würth Elektronik eiSos GmbH & Co. KG products, the customer agrees to these terms and conditions.

8 License terms
This License Terms will take effect upon the purchase and usage of the Wirth Elektronik eiSos GmbH & Co. KG wireless connectivity products. You hereby agree that these license terms are applicable to the product and the incorporated software, firmware, and source codes (collectively, “Software”) made available by Worth Elektronik eiSos in any form, including but not limited to binary, executable or source code form. The software included in any WOrth Elektronik eiSos wireless connectivity product is purchased to you on the condition that you accept the terms and conditions of this license terms. You agree to comply with all provisions under these license terms.
8.1 Limited license
Wirth Elektronik eiSos hereby grants you a limited, non-exclusive, non- transferable, and royalty-free license to use the software and under the conditions that will be set forth in this license terms. You are free to use the provided Software only in connection with one of the products from Worth Elektronik eiSos to the extent described in these license terms. You are entitled to change or alter the source code for the sole purpose of creating an application embedding the Wirth Elektronik eiSos wireless connectivity product. The transfer of the source code to third parties is allowed to the sole extent that the source code is used by such third parties in connection with our product or another hardware provided by Worth Elektronik eiSos under strict adherence of these license terms. Worth Elektronik eiSos will not assume any liability for the usage of the incorporated software and the source code. You are not entitled to transfer the source code in any form to third parties without the prior written consent of Worth Elektronik eiSos. You are not allowed to reproduce, translate, reverse engineer, decompile, disassemble or create derivative works of the incorporated software and the source code in whole or in part. No more extensive rights to use and exploit the products are granted to you.
8.2 Usage and obligations
The responsibility for the applicability and use of the Worth Elektronik eiSos wireless connectivity product with the incorporated Firmware in a particular customer design is always solely within the authority of the customer. Due to this fact, it is up to you to evaluate and investigate, where appropriate, and to decide whether the device with the specific product characteristics described in the product specification is valid and suitable for your respective application or not. You are responsible for using the Worth Elektronik eiSos wireless connectivity product with the incorporated Firmware in compliance with all applicable product liability and product safety laws. You acknowledge to minimize the risk of loss and harm to individuals and bear the risk for failure leading to personal injury or death due to your usage of the product. Worth Elektronik eiSos’ products with the incorporated Firmware are not authorized for use in safety-critical applications, or where a failure of the product is reasonably expected to cause severe personal injury or death Moreover. Worth Elektronik eiSos’ products with the incorporated Firmware are neither designed nor intended for use in areas such as military, aerospace. aviation, nuclear control, submarine, transportation (automotive control, train control, ship control), transportation signal, disaster prevention, medical, public information network, etc. You shall inform WOrth Elektronik eiSos about the intent of such usage before the design-in stage. In certain customer applications requiring a very high level of safety and in which the malfunction or failure of an electronic component could endanger human life or health, you must ensure to have all necessary expertise in the safety and regulatory ramifications of your applications. You acknowledge and agree that you are solely responsible for all legal, regulatory, and safety-related requirements concerning your products and any use of Würth Elektronik eiSos’ products with the incorporated Firmware in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by Würth Elektronik eiSos. YOU SHALL INDEMNIFY WÜRTH ELEKTRONIK EIDOS AGAINST ANY DAMAGES ARISING OUT OF THE USE OF WÜRTH ELEKTRONIK EISOS’ PRODUCTS WITH THE INCORPORATED FIRMWARE IN SUCH SAFETY-CRITICAL APPLICATIONS.

8.3 Ownership
The incorporated Firmware created by Würth Elektronik eiSos is and will remain the exclusive property of Würth Elektronik eiSos.
8.4 Firmware update(s)
You have the opportunity to request the current and actual Firmware for a bought wireless connectivity Product within the time of warranty. However, Würth Elektronik eiSos has no obligation to update modules firmware in their production facilities, but can offer this as a service on request. The upload of firmware updates falls within your responsibility, e.g. via ACC or another software for firmware updates. Firmware updates will not be communicated automatically. It is within your responsibility to check the current version of a firmware in the latest version of the product manual on our website. The revision table in the product manual provides all necessary information about firmware updates. There is no right to be provided with binary files, so-called “Firmware images”, those could be flashed through JTAG, SWD, Spi-Bi-Wire, SPI or similar interfaces.
8.5 Disclaimer of warranty
THE FIRMWARE IS PROVIDED “AS IS”. YOU ACKNOWLEDGE THAT WÜRTH ELEKTRONIK EIDOS MAKES NO REPRESENTATIONS AND WARRANTIES OF ANY KIND RELATED TO, BUT NOT LIMITED TO THE NON-INFRINGEMENT OF THIRD PARTIES INTELLECTUAL PROPERTY RIGHTS OR THE MERCHANTABILITY OR FITNESS FOR YOUR INTENDED PURPOSE OR USAGE. WÜRTH ELEKTRONIK EIDOS DOES NOT WARRANT OR REPRESENT THAT ANY LICENSE, EITHER EXPRESS OR IMPLIED, IS GRANTED UNDER ANY PATENT RIGHT, COPYRIGHT, MASK WORK RIGHT, OR OTHER INTELLECTUAL PROPERTY RIGHT RELATING TO ANY COMBINATION, MACHINE, OR PROCESS IN WHICH THE WÜRTH ELEKTRONIK EISOS’ PRODUCT WITH THE INCORPORATED FIRMWARE IS USED. INFORMATION PUBLISHED BY WÜRTH ELEKTRONIK EIDOS REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT CONSTITUTE A LICENSE FROM WÜRTH ELEKTRONIK EIDOS TO USE SUCH PRODUCTS OR SERVICES OR A WARRANTY OR ENDORSEMENT THEREOF.

8.6 Limitation of liability
Any liability not expressly provided by Würth Elektronik eiSos shall be disclaimed. You agree to hold us harmless from any third-party claims related to your usage of the Würth
Elektronik eiSos’ products with the incorporated Firmware, software, and source code. Würth Elektronik eiSos disclaims any liability for any alteration, development created by you or your customers as well as for any combination with other products.
8.7 Applicable law and jurisdiction
Applicable law to these license terms shall be the laws of the Federal Republic of Germany. Any dispute, claim or controversy arising out of or relating to this license terms shall be resolved and finally settled by the court competent for the location of Würth Elektronik eiSos’ registered office.
8.8 Severability clause
If a provision of these license terms is or becomes invalid, unenforceable, or null and void, this shall not affect the remaining provisions of the terms. The parties shall replace any such provisions with new valid provisions that most closely approximate the purpose of the terms.
8.9 Miscellaneous
Würth Elektronik eiSos reserves the right at any time to change these terms at its own discretion. It is your responsibility to check at Würth Elektronik eiSos homepage for any updates. Your continued usage of the products will be deemed as the acceptance of the change. We recommend you to be updated about the status of new firmware and software, which is available on our website or in our datasheet and manual, and to implement new software in your device where appropriate. By ordering a wireless connectivity product, you accept these license terms in all terms.

More than you expect

Contact:
Würth Elektronik eiSos GmbH & Co. KG
Division Wireless Connectivity & Sensors
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74638 Waldenburg
Germany
Tel.: +49 651 99355-0
Fax.: +49 651 99355-69
www.we-online.com/wireless-connectivity

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