ARINC Advanced Guide
This advanced guide is intended for users that are already familiar with the ARINC 825 specification and wish to integrate a Hargrave Device into an existing ARINC 825 CAN 2.0B system.
This advanced guide will cover details regarding the way the Hargrave ARINC specification implements the ARINC 825-4 specification. This guide contains sub-sections for each of the LCCs that are implemented.
Normal Operating Channel (NOC)
All control and telemetry are broadcast on the NOC use one-to-many identifiers. The traditional 14bit ARINC 825 Data Object Codes (DOC) are broken up into two separate sections following MSB:
- 7 bit Controller Function Code (CFC): Used for identifying the packet function
- 7 bit Controller Identifier (CID): Used for identifying controllers and/or controller groups.
The Controller Identifier (CID) is the device Server Identifier (SID) for directed messages or the group identifier (Group CID) for broadcast message, which will target a range of SID values. Server Identifiers are pre-configured via device settings between 1-127. The multicast SID of 0 will be ignored.
For motor controllers the Function Code Identifier (FID) is defaulted to 11 - Engine Controls, however this is configurable in device settings.
Control and Telemetry Messages
All control and telemetry messages are transmitted on the NOC. Details about the control and telemetry message set can be found at the below link:
Node Service Channel (NSC)
All messages implemented on the Node Service Channel use peer-to-peer CAN identifiers.
Standard Node Services
The following standard node services are implemented:
SFC | Node Service | Has Response | SCS Controlled | Notes |
|---|---|---|---|---|
0x0 | Node Identification Service (IDS) | Yes | No | Profile ID and Sub-ID are configurable through device settings. LRU is the device PCBA, trucated to 2 bytes. |
0x1 | Node Synchronisation Service (NSS) | No | No | Commands the device to insert a marker in on-board logging (on supported devices) |
0x2 | Data Upload Service (DUS) | Yes | Yes | Firmware can be updated using the Operating System (0x05) destination identifier. Message and block separation values are flexible and should be adjusted based on system capabilities. |
0x5 | Non-Volatile Storage Service (NVS) | Yes | Yes | Saves device settings and commands a device restart. Password: 0xABBA |
0x6 | Node-ID Setting Service (NIS) | Yes | Yes | Changes the SID of the device. This change will not persist through a restart. |
0x7 | Service Control Service (SCS) | Yes | No | Implemented with a 60 second timeout from last activity for a given node service. Custom node services used for parameter handling all share the same SCS lock. Control Codes: Enable: 0xEE Disable: 0xDD |
Custom Node Services
The following link details the custom node services that are implemented:
Test and Maintenance Channel (TMC)
All messages implemented on the Test and Maintenance Channel use peer-to-peer CAN identifiers.
Periodic Health Status Message (PHSM)
The Periodic Health Status Message (PHSM) defined in ARINC 825 is broadcast on the Test and Maintenance Channel at 1Hz by default, the SMT bit is set indicating that this is ARINC 825-4. The rate at which the PHSM is broadcast can be configured in device settings.
Hargrave Protocol Tunnel Messages
To facilitate use of the Hargrave Configurator with devices operating with ARINC a series of tunnel messages have been implemented on the Test and Maintenance Channel. The content of these messages is opaque as indicated by the private (PVT) CAN ID bit being set.
A device will only respond to tunnel messages from the pre-configured tunnel FID. By default this is the Temporary Test and Maintenance FID of 127. Setting the tunnel FID to 0 will disable the tunnel and the device will ignore private messages on the TMC. The SMT bit will be set depending on the direction of the message.