What is Wireless M Bus?
This page describes what is wireless M Bus and mentions Wireless Meter Bus basics. It mentions wM-Bus kits (hardware and software).
The full form of wM-Bus is Wireless Metering Bus. It is specified in EN13757-4 standard. This standard mentions communication between meter and other components. The system components include read-out devices and data collectors. These devices can be stationary or mobile.
The figure depicts Wireless M-Bus communication system block diagram. The communication between meter and other system components can be either one-way or two-way. There are different physical layer modes. These wM-Bus PHY modes are mentioned in the table-1. The PHY modes are S-mode, T-mode, R-mode, N-mode, C-mode, F-mode etc.
|WM-Bus PHY Mode||Description|
|S-Mode(Stationary Mode)||S1-Mode(One way)
S2-Mode (two way)
|T-Mode (Frequent Transmit Mode)||T1-Mode (one way)
|R-Mode (Frequent Receive Mode)||R2-Mode (two way)|
|N-Mode (Stationary Mode)||N1 Mode(one way)
N2 Mode (two way)
|C-Mode (Frequent Transmit Mode)||C1 Mode (one way)
C2 Mode (two way)
|F-Mode (Frequent Transmit Mode)||F1 Mode (one way)
F2 Mode (two way)
wM-Bus frequency bands
Following table-2 mentions wM-Bus modes and their SRD frequency bands.
|wM Bus Mode||SRD Frequency Band|
|S1-Mode, S2-Mode||868 MHz|
|T1-Mode, T2-Mode||868 MHz|
|C1-Mode, C2-Mode||868 MHz|
|N1-Mode, N2-Mode||169 MHz|
|F1-Mode, F2-Mode||433 MHz|
Wireless M-Bus(wM-Bus) Kits
TEXAS INSTRUMENTS have CC112x and CC120x series supporting Wireless M-Bus Transceiver functionalities. It supports frequency bands 868,433 and 169MHz. It is ETSI 300-220 V2.3.1 compliant.
RENESAS has developed wireless M-Bus protocol stack.
They have Wireless M-Bus interface board which supports following features.
• It supports T1,S1,T2,S1-m,C1,S2,C2,N1,F2 and N2 modes as per EN 13757-4 standard document. The WM-Bus Kit supports 169 and 868 MHz frequency bands. The protocol stack source code is available.In addition software libraries of data-link layer and application layer is also available.
Wireless M-Bus tutorial
Refer Wireless M-Bus tutorial>> which covers following:
• System Features
• WM-Bus network
• WM-Bus Protocol Stack
• WM-Bus Frame formats A and B