FORMAT OF DATA AND DESCRIPTOR STRUCTURE

The ZETSENSOR sensor parameters and settings are stored in internal storage in the form of the C language structures. A descriptor structure corresponds to each of the structures available for reading and writing.
The structure format is shown below (see Figure 1).

Figure 1. Format of ZETSENSOR data structure 

STRUCT_HEAD has the following form:
typedef struct {
unsigned int size : 12;
unsigned int struct_type : 10;
unsigned int status : 10;
unsigned int write_enable : 16;
unsigned int usCRC16 : 16;
} STRUCT_HEAD;
where:
size – structure size;
struct_type – structure ID;
status – error ID;
write_enable – status in data writing;
usCRC16 – checksum.
The most important structures include DEV_PAR (structure with sensor identification data, structure ID is 0x18C) and CHANNEL_PAR (structure with the sensor measuring channel settings, structure ID is 0x0D0)
The DEV_PAR structure has the following form:
typedef struct {
STRUCT_HEAD head;
long type;
unsigned long long serial_num;
long compile_time;
long edition_time;
unsigned long dev_addr;
} DEV_PAR;
where:
type – sensor type ID;
serial_num – sensor serial number;
compile_time – sensor software version;
edition_time – sensor settings last change time;
dev_addr – device address (1 to 63).
The CHANNEL_PAR has the following form
typedef struct {
STRUCT_HEAD head;
float value;
float frequency;
char measure[8];
char channel_name[32];
float min_level;
float max_level;
float reference;
float sense;
float resolution;
} CHANNEL_PAR;
where:
value – current measured value, measurement unit;
frequency – data refresh rate in the channel, Hz;
measure – unit for a channel;
channel_name – channel name;
min_level – minimum measured value for a channel, unit;
max_level – maximum measured value for a channel, unit;
reference – reference value, unit;
sense – sensitivity, V per unit;
resolution – sensitivity threshold, unit;
The structures are located in the sensor memory one after another.