ECM NH3CAN, Инструкция по эксплуатации, Страница: 5 / 35

5
1.0 Introduction and General Notes
1.1
Introduction
The
NH
3
CAN
kit is a ceramic sensor-based NH
3
, measurement system that communicates and
is configured via the CANopen protocol. Its primary application is for the analysis of
combustion systems and their after-treatment.
1.2
General Notes
1.
All numbers are decimal unless preceded by the “0x” suffix which denotes a hexadecimal
value: e.g. 0x0F = 15.
2. 1 byte contains 8 bits.
3. One “unsigned character” contains 1 byte (unsigned 8) and has a range of
0x00 – 0xFF (0 – 255).
4. One “string” contains 1 byte (unsigned 8) and has a range of 0x00 – 0xFF (0-255). The
number represents an ASCII character.
5. One “unsigned integer” contains 2 bytes (unsigned 16) and has a range of
0x0000 – 0xFFFF (0 – 65535).
6. One “unsigned long” contains 4 bytes (unsigned 32) and has a range of
0x00000000 – 0xFFFFFFFF (0 – 4294967295).
7. One “single float” contains 4 bytes (single float) that represent a decimal number using the
IEEE-754 standard.
8. A “lo” byte and “high” byte can be combined as follows to form a 2 byte unsigned integer:
e.g. lo byte = 0x10 (16), hi byte = 0x1F (31), 2 byte integer = 0x1F10 = 31*256+16 = 7952
9. “lo” byte can also be referred to as the least significant byte (LSB).
10. If a subindex value for an Object Dictionary (OD) is unspecified, it is assumed to be 0x00.
11. Data value boxes that are shown as blank are reserved; do not use these locations.
12. All messages on the CAN bus must have a unique identifier which is referred to as “CANid”
in this manual but can also be referred to as “COB ID, communication object identifier”.