Wavecom W61PC V7.5.0 - Manual (Page 159)

WAVECOM Decoder W61PC/LAN Manual V7.5 Transmission Modes  149
The receiver addressing only takes place within the appropriate batch. After decoding its address the re-
ceiver will wait on the same frequency for data. Data may be transmitted within the same batch, within
another subsequence batch or within subsequent subsequences.
Each batch is subdivided into four parts: Synchronization, system information, address and text.
Protocol Structure
System Information
Network and system information is transmitted within the system subdivision of a batch. The system in-
formation is divided into two parts, System Information (SI) and Supplementary System Information
(SSI).
Depending on the value of the SSI flag the Supplementary System Information (SSI) carries information
on zone, local time and date. Another option displays day of week, month of year and year.
Data
ERMES transmits data in fixed-length frames of 36 bits. A frame may carry an additional data field and the
text data.
Message Frame (MHEAD)
The Variable Information Field (VIF) has two main options depending of the status bit ALL = 0 or ALL = 1.
Variable Information Field Without Supplementary Information