Wireless M-Bus is optimized for battery supply, therefore the module (Slave in the meter) will only listen for a short period after a transmission. In mode T the listening window is from 2-3 ms after transmission; in mode S it is from 3-50 ms, and for mode N it is a short window afer 100ms or 1.1/2.2 seconds depending on the data rate. The master module must therefore transmit any message to the Slave within a very precise time window. The MBUS3 and MBUS4 modules has built-in support taking care of this timing using a mailbox and an intelligent message generator.
Last Update: August 8, 2017