Casals REINTAIR S 300 AC Manual De Uso Y Mantenimiento página 52

REG REINTAIR COMMUNICATION PROTOCOL
The protocol used is MODBUS RTU mode with the following characteristics:
RS-485 (2 wire). Maximum number of elements on the bus: 32 (1 master + 31 slaves).
- Communication speed: 9600 baud.
- Data format:
- 8 bits.
- No parity.
- 1 stop bit.
- 16 bit registers (2 bytes).
Variable format: High Word First [H / L].
- CRC according to polynomial x16 + x15 + x2 + 1.
Note: It is recommended to retry communications. Timeout: 1sec.
Note: Minimum recommended Wait To Send time: 100ms.
READING OF RECORDS
For reading registers it is possible to use command codes 3 or 4 with the following message structure:
Slave No. (1 byte) - Code (03 or 04) (1 byte) - Address of the 1st register to read (00-XX) (2 bytes) - No. of registers to read (00-YY) (2 bytes) - CRC16 (2 bytes)
Maximum number of records to read in the same message = 55 (from record 0 to record 54)
The regulator's reply has the following message structure:
Slave number (1 byte) - Code (03 or 04) (1 byte) - Number of data bytes (XX) (1 byte) - Data (AA-BB-CC-DD ...) (2 bytes for each register) - CRC16 (2
bytes) Number of data bytes = 2 * Number of records to read
RECORD WRITING
For writing registers, command code 6 is used with the following message structure:
Slave number (1 byte) - Code (06) (1 byte) - Address of the register to write (00-XX) (2 bytes) - Data to write to the register (AA-BB) (2 bytes) - CRC16 (2 bytes)
The regulator's reply has the following message structure:
Slave number (1 byte) - Code (06) (1 byte) - Address of the written register (00-XX) (2 bytes) - Data written in the register (AA-BB) (2 bytes) - CRC16 (2 bytes)
MISTAKES
If a code other than the indicated read or write code is used, the response received is:
Slave number - OR code 80Hex - Error code (1) - CRC16 (2 bytes)
If you try to read or write access to a record with a non-existent address, the response received is:
Slave number - OR code 80Hex - Error code (2) - CRC16 (2 bytes)
If you try to write to a read-only record or try to write an illegal value to a record, the response you receive is:
Slave number - OR code 80Hex - Error code (3) - CRC16 (2 bytes)
RECORD MAP
The unused bits in the following registers are 0.
Note: In some communication programs, the first word address is configured as 400001, so register 0 of the controller corresponds to the word
address 400001. In summary, the word address to which each register of the controller corresponds is calculated adding 1 to the record number of
the record map described below.
Device ID record
Record 0: 143 [read-only].
- The controller always responds 143 as a sentinel point in 16-bit binary.
Read / write registers
Record 1: Communications address [read / write].
- The value that is sent is the value of the address (1 to 240) in 16-bit binary.
Default value: 1 [1].
If the controller is connected to a serial communications network, it is not possible to configure any equipment on the network at address 245,
since the Regulator also responds to that direction.
BROADCAST ADDRESS: Address 250 (the controller receives the communication, but does not respond). All writing records are broadcast.
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