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Table of schedules and setpoints:
Communication protocol of the sensor regulator SCO2-IAQ
The protocol used is MODBUS mode RTU with the following characteristics:
RS-485 (2 wire). Maximum number of elements on the bus: 32 (1 31 slaves).
Speed communication: 9600 baud..
Data formats:
N
8 bits.
N
No parity.
N
1 bit di stop.
Registers of 16 bits (2 bytes).
Variable format: High Word First [H/L].
CRC following polynomial x16 + x15 + x2 + 1.
Note: It is recommended to retry communications. Timeout: 1sec.
Note: Minimum time Wait To Send recommended: 100ms.
Reading records
For reading registers it is possible to use command codes 3 or 4 with the following message structure:
Nº slaves (1 byte) – Code (03 ó 04) (1 byte) – Direction of the 1st register to read (00-XX) (2 bytes)
Nº of register to read (00-YY) (2 bytes) – CRC16 (2 bytes)
Nº maximum of registers to read in the same message = 57 (from register 0 to register 56)
The response from the sensor regulator has the following message structure:
Nº slave (1 byte) – Code (03 ó 04) (1 byte) – Nº de bytes de datos (XX) (1 byte) –
Datos (AABB-CC-DD…) (2 bytes para cada Register) – CRC16 (2 bytes)
Nº de bytes de datos = 2 * Nº de Registers a leer
Write de registers
Para la write de Registers se utiliza el Code de comando 6 con la siguiente estructura de mensaje:
Nº slave (1 byte) – Code (06) (1 byte) – Dirección del Register a escribir (00-XX) (2 bytes)
– Dato a escribir en el Register (AA-BB) (2 bytes) – CRC16 (2 bytes)
La contestación del regulator sonda tiene la siguiente estructura de mensaje:
Nº slave (1 byte) – Code (06) (1 byte) – Direction of the wrote register (00-XX) (2 bytes) –
wrote said in the register (AA-BB) (2 bytes) – CRC16 (2 bytes)
ENGLISH
Summary of Contents for Kit Vario CO2
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