The software supports visibility message (MES 2) of Vaisala FS11 and FS11P. FS11, and FS11P MES 2 is a message of fixed length where both visibility and background luminance values are shown.
MES 2 keeps the message as short as possible for sites with very limited data transmission bandwidth. Use it only if data transmission speed is an issue at the installation site.
| Vaisala FD12 MES 2 is not supported. |
MES 2 has measurement data on one line. Detailed alert information can be represented on an optional status line. The status line is a product-specific feature.
MES 2 message data fields
The following example shows sample measurement data, the corresponding data element fields, and the character positions.
VIS 02000 AL 0 BL 01000 AL 0
VIS visii AL v BL bbbbb AL b
1234567890123456789012345678| If data on is not available or it is categorized as non-valid, the characters on the data field are replaced by SLASH (0x2F). |
| The field delimiters, characters 4, 10, 13, 15, 18, 24 and 27, are SPACE (0x20). |
| Position | Name | Sample | Description | Value/Range |
|---|---|---|---|---|
| Line 1 | ||||
| 1-3 | VIS | VIS | Visibility identifier tag | VIS |
| 5-9 | visii | 02000 | MOR (m), 1 minute average |
0–99999 or ///// Leading zeros are included. |
| 11-12 | AL | AL | Alert identifier of visibility measurement | AL |
| 14 | v | 0 | Visibility measurement alert | Single character 0 = OK I = Info W = Warning A = Alarm 1 |
| 16-17 | BL | BL | Background luminance identifier | BL |
| 19-23 | bbbbb | 01000 | Background luminance (cd/m2) |
0–99999 or ///// Leading zeros are included. |
| 25-26 | AL | AL | Alert identifier of background luminance "AL" | AL |
| 28 | b | 0 | Background luminance measurement alert | Single character 0 = OK I = Info W = Warning A = Alarm 1 |
| Line 2 | ||||
| A product-specific line that contains status and alert data. | ||||
The first alert character (in position 14) is the most severe status level of any FD70 maintenance or hardware alerts (configuration alerts are not included).
Example of MES 2 with FS11 framing
In the following examples, the device identifier is set to A.
Without status line:
SHFSASXVIS 02000 AL 0 BL 01000 AL 0EXCSUMETCRLFWith status line:
SHFSASXVIS 02000 AL 0 BL 01000 AL 0CRLF
<STATUS LINE CONTENT>CRLF
EXCSUMETCRLFExample of MES 2 without framing
Without status line:
VIS 02000 AL 0 BL 01000 AL 0With status line:
VIS 02000 AL 0 BL 01000 AL 0CRLF
<STATUS LINE CONTENT>CRLFAlert characters in FS11 and FS11P: 0, I, W, A, E. Alert character E is not used in FD70.