The Pre-Defined Connection Set
for an 8-bit Message Identifier

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TECHNOLOGY
Message IDs
Layer-2 Driver
MM2.h
Layer-7 API
MM7.h

 

Using an 8-bit Message Identifier

Per default, MicroMessaging uses an 8-bit message identifier and allows for a total of 31 nodes (based on a 3-bit Node ID with node '0' being reserved). In the pre-defined connection set the 5 least significant bits are used for the node ID and the 3 most significant bits define the function code.

Bits 7..5 Bits 4..0
Function Code (0-7) MicroMessaging Node ID (1-31)

Default Message Identifier Assignment

The following table lists the default message identifier assignment of MicroMessaging.

Function
Code
Node
ID
Message
ID
MicroMessaging
Usage
0 0 00h Master Control Message
0 1-31 01h-1Fh Emergency
1 0 20h Poll Message
1 1-31 21h-3Fh Process Data Channel 1
2 0 40h Reserved
2 1-31 41h-5Fh Process Data Channel 2
3 0 60h Reserved
3 1-31 61h-7Fh Process Data Channel 3
4 0 80h Reserved
4 1-31 81h-9Fh Process Data Channel 4
5 0 A0h Reserved
5 1-31 A1h-BFh Service Data Request Channel
6 0 C0h Reserved
6 1-31 C1h-DFh Service Data Response Channel
7 0 E0h Master Status
7 1-31 E1h-FFh Slave Status