Particle Measuring Systems LASAIR II 310 Operator's Manual page 177

Appendix F: Multidrop Protocol (MiniLaz Emulation) Appendix F: Multidrop Protocol (MiniLaz Emulation)
Multi-Drop Command Coding Overview Multi-Drop Command Coding Overview
Page F-2 Page F-2
Commands in the PMS protocol are formatted in the following manner. For Commands in the PMS protocol are formatted in the following manner. For
users wishing to write their own drivers, basic communication routines are users wishing to write their own drivers, basic communication routines are
available from Particle Measuring Systems. available from Particle Measuring Systems.
Formatting Command Codes Formatting Command Codes
To properly format a command code: To properly format a command code:
Add the address of the instrument to the beginning o Add the address of the instrument to the beginning of the command string. The
1 1
address is an unsigned 16 bit integer between 0 and 99. address is an unsigned 16 bit integer between 0 and 99.
Add a 16 bit checksum of the data and address to the end of the packet. The Add a 16 bit checksum of the data and address to the end of the packet. The
2 2
checksum is an unsigned sum of every address and data byte. checksum is an unsigned sum of every address and data byte.
At this point the packet should look like this: At this point the packet should look like this:
ADDR_HIGH_BY ADDR_HIGH_BYTE | ADDR_LOW_ TE | ADDR_LOW_BYTE | DATA_1 |
DATA_N | CHECKSUM_HIGH DATA_N | CHECKSUM_HIGH_BYTE |
3 3 ASCII characters not in the range of 0x20 to 0x7E must be converted to a 2-byte ASCII characters not in the range of 0x20 to 0x7E
sequence using the following table: sequence using the following table:
O O R R I I G G I I N N A A L L B B Y Y T T E E
byte < 0x20 byte < 0x20
0x7B 0x 7B <= <= by byte te < 0
0x80 <= byte < 0xC0 0x80 <= byte < 0xC0
0xC0 <= byte 0xC0 <= byte
4 4 Pre-append an ASCII <STX> character (0x02) to Pre-append an ASCII <STX> character (0x02) to the data stream, and post-
append an ASCII <ETX> character (0x03) to the data stream. append an ASCII <ETX> character (0x03)
5 5 Data is ready to transmit. Data is ready to transmit.
Multi-Drop Commands Multi-Drop Commands
CCAL CCAL
Response: Response:
"RCAL yyyy/mm/dd" "RCAL yyyy/mm/dd"
Returns the Returns the last calibration last calibration date.
least once a year). least once a year).
CCONT n CCONT n
Response: " Response: "
RCONT m RCONT m
LASAIR II II Operator's LASAIR
BYTE | DATA_1 | DATA_2 | ... |
_BYTE | CHECKSUM_LOW CHECKSUM_LOW_BYTE
T T R R A A N N S S M M I I T T T T E E D D B B Y Y T T E E S S
0x7B, byte+0x20 0x7B, byte+0x20
< 0x8 x80 0 0x7C 0x 7C, b , byt yte- e-0x 0x5B
0x7D, byte-0x60 0x7D, byte-0x60
0x7E, byte-0xA0 0x7E, byte-0xA0
to the data stream.
date. (A LASAIR (A LASAIR II should
" "
Operator's Manual Manual
f the command string. The
DATA_2 | ... |
_BYTE
must be converted to a 2-byte
5B
the data stream, and post-
II should be calibrated be calibrated at at