Vaisala PA50 pressure message can be used to
receive pressure data. Data fields are separated with whitespaces and missing data is
identified with solidi (/) or asterisk (*) characters:
<SOH>P<STX>1<SP><p><SP><p3h><SP><a3h><SP><p1><SP>p2><<SP><p3><err><ETX><chk>
<CR><LF>| Name | Description |
|---|---|
<SOH> |
ASCII character, Start of header #001 |
P |
Fixed character |
<STX> |
ASCII character, Start of text, #002 |
1 |
Fixed character |
<SP> |
Whitespace |
| <p> | Pressure (average of measurements <p1>, <p2>, and <p3>) |
| <p3h> | 3‑hour trend, pressure change during last 3 hours |
| <a3h> | 3‑hour tendency according to WMO code table Manual on Codes Vol. 1.1, International Codes, Part A – Alphanumerical Codes, 1995 Edition, WMO – No. C, Code Table 0200:a. |
| <p1> | Pressure from barometer module 1 |
| <p2> | Pressure from barometer module 2 |
| <p3> | Pressure from barometer module 3 |
| <err> | Transducer status code, one to three characters, for example
000 |
<ETX> |
ASCII character, End of text, #003 |
| <chk> | Modulus-256 checksum of message sent so far, hexadecimal format |
<CR> |
Carriage return code, ASCII 0Dh |
<LF> |
Line feed code, ASCII 0Ah |
| Vaisala PA50 pressure message does not contain a sensor ID. Therefore multiple messages from the same communication channel cannot be identified. |
Examples of PA50 pressure message
<SOH>P<STX>1 1002.50 -0.01 7 1002.60 1002.44 1002.52 000<ETX>70<CR><LF><SOH>P<STX>1 1009.18 ***.* * 1009.2 1009.2 1009.2 000<ETX>D6<CR><LF>PTB330 FORM command to set PA50 pressure message
FORM #001 "P" #002 "1 " 4.2 P " " P3H " " A3H " " P1 " " P2" " P3 ERR #003 CS2 #rn