MAIMAN ELECTRONICS SF8025 - Page 25

Maiman Electronics SF8025, SF8075, SF8150, SF8300
24
Text-plain mode
All commands in text-plain mode should be in ASCII.
WARNING! If you enable the checksum it will change format of commands. After <CR>
symbol you will be write 2 bytes of checksum and last byte will be <LF> (0Ah – “new line” symbol).
Checksum is computed for all bytes of command before checksum bytes (including<CR> symbol).
All answers of the device will also contain a checksum, including K-type and E-type answers.
Checksum is computed by CRC-CCITT-8 algorithm. This is the main difference between the format
of commands for the extended protocol and standard protocol.
The format of commands for enabled checksum
Number of
byte
Value
Comment
1
P,J,K,E
Type of command
2-5
Number of parameter
Hex-number of value
6
‘space’ symbol (20h)
(does not use for J and E-type commands)
7-10
New value of the parameter
Hex-value of parameter (does not use for J and
E-type commands)
11
‘return carriage’ symbol<CR>
(0Dh)
End of value
12-13
Checksum
CRC checksum of the first 11 bytes (for J and E-
type commands checksum is computed for the
first 6 bytes), including <CR> symbol.
14
‘new line’ symbol<LF> (0Ah)
End of command
Possible problems
1. The device waiting for symbol <LF>. If <LF> symbol does not received and buffer is overflowed,
then all symbols after overload will be processed as a new command. The device returns an
error. In this case, it is recommended to send the <LF> symbol. The device will generate an
error and clear the buffer for the next command.
2. All symbols after the <LF> symbol will be processed as a new command.