STAMOS S-LS-96 Manual De Instrucciones página 50

Message transmission must start with an interval of at least 3.5 characters.
The data frame must be a continuous stream of data transmission, if before
the end of the frame there is a break longer than 3.5 characters, the
receiving device refreshes the incomplete message and reads that the next
byte is the beginning of a new message.
Similarly, if the gap between two separate messages is less than 3.5
characters, the receiving device will read the two messages as one.
The standard structure of an information frame is as follows:
Beginning Address
of the
frame
T1-T2-T3- 8 bites
T4
Description of the frame fields:
- Address - The master selects the slave by placing the address of the slave to
connect to in the address field.
The address range for a single slave is 1...128 (decimal), the address is sent in
hexadecimal format.
Address 0 is a Broadcast address, which is received and recognized by all
slaves, but it is not possible to send a reply when a message is received.
- Function - The field encoding range is 1...255 (decimal). The function code
informs the slave device what command to execute, e.g. read/write data of a
registry group, etc.
- Data - this field contains additional information sent to the slave regarding
the command sent in the function field, e.g. register addresses.
- CRC check - when CRC is generated, the younger byte is first and the older
byte is second.
Caution: The interval between the communication frame response and the
frame generated by the device when the communication rate is 9600 bps
should be greater than 5ms.
Function Data
8 bites N*8Bit
CRC Frame
control end
16Bit T1-T2-T3-
T4