znv_constitutents

IDEC ZNV constituent reference
Based on the Read_regs ZNV extraction, idec_operation.BIN, WindowsSimulatorFW_HG2J.dll, and Downloader.exe.
1. Project component extensions
Extension	Identification / probable purpose	Evidence
.t2f	Core project data or configuration; exact schema unknown	Extracted; PROJECT.T2F explicitly referenced by Downloader
.b2f	Core project data; exact purpose unknown	Extracted; PROJECT.B2F explicitly referenced
.c2f	Additional core project data; exact purpose unknown	Runtime, simulator, PROJECT.C2F in Downloader
.d2f	Project configuration or definitions; extracted content includes gzip-compressed XML	Extracted; runtime and simulator
.e2f	Unknown project component	Extracted; runtime and simulator
.i2f	Unknown project component	Extracted; runtime and simulator
.l2f	Unknown project component or library-related data	Extracted; runtime and simulator
.m2f	Grouped resource data, possibly associated with /MG; function unconfirmed	Extracted as mg0001.m2f; runtime and simulator
.o2f	Screen-associated object/resource data; keyboard content is possible, not established	Extracted as bs0001.o2f etc.; runtime and simulator
.p2f	Unknown project component	Extracted; runtime and simulator
.q2f	Unknown optional component	Runtime and simulator
.s2f	Unknown project component	Extracted; runtime and simulator
.u2f	Unknown optional component	Runtime and simulator
.v2f	Unknown optional component	Runtime and simulator
.X2F	Unknown component; uppercase spelling appears explicitly in both binaries	Runtime and simulator
.F2F	Possibly recipe-related resource, given nearby /RCP	Runtime, simulator, Downloader
.G2F	Communication driver resource	DRIVER1.G2F–DRIVER4.G2F in runtime and simulator
.j2f	Unknown; possibly specific to older or other HMI families	Downloader only
.k2f	Unknown; possibly specific to older or other HMI families	Downloader only
.o1a	Unknown; possibly an older-family screen/resource format	Downloader only

Confidence distinction: The first ten entries that appeared in Read_regs are verified ZNV members. The remaining extensions are software-recognized candidates, not yet demonstrated as members of an HG2J ZNV.
2. Additional named files and resources
These names were identified in the HG2J runtime or Downloader. They belong to the broader project-transfer and installation vocabulary; some may be ZNV constituents, while others may be staging files or runtime resources.
Filename or pattern	Description
PROJECT.COD	Project-related data file; contents unknown
PROJECT.OUT	Project-related data file; contents unknown
PROJECT.CMT	Project-related data file; contents unknown
PROJECT.T2F	Core project file
PROJECT.B2F	Core project file
PROJECT.C2F	Core project file
DRIVER.G2F	Generic communication driver resource name in Downloader
DRIVER1.G2F–DRIVER4.G2F	Numbered communication driver resources
HG2F.BIN	Embedded executable/resource referenced in HMI installation handling; exact function unconfirmed
FT2J_PLCSYS.BIN	PLC/system-related resource; precise role unknown
EXFONT.BIN	External-font resource, inferred from filename
logo.ppm	Logo image
logo.ini	Logo configuration
.bac	Probably BACnet-related resource
.eip	Probably EtherNet/IP-related resource
.mqt	Probably MQTT-related resource

The last three protocol-related interpretations are supported by their conventional abbreviations and the HMI's communication capabilities, but we haven't examined their contents.
3. Identified naming prefixes and directories
Name	Possible significance
PROJECT	Project-wide data
BS	Base screens (probable)
MG	Grouped resource data; precise meaning unknown
SA	Unknown resource category
RCP	Recipes (probable)
HGWORK	Temporary installation/extraction workspace
DRIVER	Communication drivers
EXFONT	External fonts
NVDATA	Project transfer-data storage
RECIPE	Recipe resources
PICTURE	Picture resources
FONT	Font resources
SYSTEM	HMI system files
LIB, MLIB, SLIB	Library-related directories; specific distinctions unknown
USRDAT	User/project data directory

Downloader also identifies the configuration keys BaseScreenDataFilePrefix, PopupScreenDataFilePrefix, RecipeDataFilePrefix, PartsLibraryDataFile, CompressBitmapDataFile, and HGLibraryFile.

Those names are useful evidence of supported resource categories, but they do not yet establish a one-to-one mapping to specific extensions.
4. ZNV container structures
Apart from identifiable constituent files, we've observed:
Structure	Current understanding
ZNV signature	Package identification
Record/directory structures	Used by our extractor to identify constituent names, offsets and sizes
XOR32 transformations	Previously identified in ZNV encoding/repacking
Gzip streams	Present within at least some constituent data
HGDATA01	Structured binary region observed in ZNV and installed ROM; purpose unresolved
Additional binary tables	Observed around HGDATA01, but not sufficiently decoded

We should distinguish the ZNV container from the files it contains. The HGDATA01 structure is not yet established as a separate file or constituent type.
5. What I consider established
Verified ZNV extensions
10

Shared HG2J runtime/simulator extensions
17

Distinct extension candidates across examined software
20


The 17 shared runtime/simulator extensions include the 16 project-component extensions plus .G2F. The 20 total include Downloader's .j2f, .k2f, and .o1a.
Important remaining limitations
We have not verified whether all 20 extensions can occur inside a modern HG2J ZNV. Some may belong only to older HMI families, transfer workspaces, or internal intermediate files.

We also haven't established which optional project features cause .q2f, .u2f, .v2f, .c2f, .X2F, or .F2F to be generated.