Message prefixes
- Last UpdatedApr 24, 2025
- 1 minute read
The table below lists the characters that are used to precede a string of bytes to indicate the type of message.
|
Prefix |
Description |
|---|---|
|
M |
This indicates that what follows is a message from the Omnicomm. |
|
S |
This indicates that what follows is a message from Software Analyzer (SWANA). |
|
Q |
This indicates that the message was a query from the Omnicomm. |
|
R |
This indicates that the message was a reply from the RTU. |
|
X |
This indicates that the message contains errors and was discarded by Omnicomm (a spurious message). Spurious messages commonly result from the host timing out before the remote is able to respond. Since the remainder of the message arrives before the host transmits its next query, these bytes are unexpected and are labeled spurious. Spurious bytes are not displayed until after the next poll. |
Note: When SWANA is configured to receive messages from several Omnicomm connections, the messages from the connections may be interleaved (for example, query from one connection may be followed by a response from another connection). The connection name, which appears in the message header, should be noted whenever multiple connections are configured.