Technical Information
The MESSAGE is a string with the following format:
<STX>+<ADDR>+<WIN>+<COM>+<DATA>+<ETX>+<CRC>
Where:
When a data is indicated between two quotes ('...') it means that the indicated data
NOTE
is the corresponding ASCII character.
Table 14 Data type
Data Type
Logic (L)
Numeric (N)
Alphanumeric (A)
The addressed SLAVE will respond with an ANSWER whose structure depends
from the MESSAGE type. When the MESSAGE is a reading command, the SLAVE
will respond transmitting a string with the same structure of the MESSAGE.
The controller can answer with the following response types:
MS40-S User Manual
<STX> (Start of transmission) = 0x02
<ADDR> (Unit address) = 0x80 (for RS 232)
<ADDR> (Unit address) = 0x80 + device number (0 to 31) (for RS 485)
<WIN> (Window) = a string of 3 numeric character indicating the window
number (from '000' to '999'); for the meaning of each window see the relevant
paragraph.
<COM> (Command) = 0x30 to read the window, 0x31 to write into the window
<DATA> = an alphanumeric ASCII string with the data to be written into the
window. In case of a reading command this field is not present.
The field length is variable according to the data type as per the following table:
Field Length
1
6
10
<ETX> (End of transmission) = 0x03
<CRC> = XOR of all characters subsequent to <STX> and including the <ETX>
terminator. The value is hexadecimal coded and indicated by two ASCII
character.
Valid Characters
'0' = OFF
'1' = ON
'-', '.', '0' . . . '9' right justified with '0'
from blank to '_' (ASCII)
211