PLC profiles

Each profile selects the command family and device-layout assumptions used by the serial MC Protocol codecs.

Choose one explicit profile in your application or configuration UI. The library intentionally does not infer it from ReadTypeName, CPU model text, or omitted configuration.

The supported device inventory is maintained in the shared MC Protocol Serial supported registers page.

Verified hardware available for validation

The maintainer owns the hardware listed below. Communication has been verified on this hardware, and it is available for focused reproduction and validation when a problem is reported.

"Verified" does not mean that every library feature has been tested on every listed PLC or module. Exhaustively testing every combination would require a prohibitive amount of work.

PLC family	Serial hardware owned by the maintainer
MELSEC iQ-R	`RJ71C24-R2`, `RJ71C24-R4`
MELSEC iQ-F	`FX5U-32MR/DS`, `FX5UC-32MT/D`
MELSEC-L	`LJ71C24`
MELSEC-Q	`QJ71C24N`

Explicit selection is required

Always select one concrete PlcProfile value before sending real PLC requests.

PlcProfile::Unspecified is a configuration error, not a fallback profile.
No profile is inferred from CPU model text, response data, serial settings, or device strings.
Short names and case variants are rejected by text parsing.
Linux CLI wrappers require both MCPROTOCOL_FRAME and MCPROTOCOL_PLC_PROFILE; neither value is auto-filled.

Use plc_profile_display_name(profile) for UI labels. Store and parse the canonical value from plc_profile_name(profile), not the display text.

Profiles

Canonical profile	Display name	Hardware	API selector	Current internal grouping / status
`melsec:iq-r`	MELSEC iQ-R	MELSEC iQ-R serial modules	`PlcProfile::MelsecIqR`	iQ-R command/device-layout branch. Manual-derived request-shape differences include iQ-R subcommands and wider device references.
`melsec:iq-l`	MELSEC iQ-L	MELSEC iQ-L serial modules	`PlcProfile::MelsecIqL`	Separate public profile using Q/L-compatible serial MC request shapes. Long timer/counter devices, `LZ`, `RD`, and `Un\HG` are rejected for serial MC.
`melsec:iq-f`	MELSEC iQ-F	MELSEC iQ-F / FX5 serial paths	`PlcProfile::MelsecIqF`	Separate public profile using the confirmed FX5 C4 binary support surface. Unsupported FX5 devices and routes are rejected locally.
`melsec:qcpu`	MELSEC-Q	MELSEC-Q serial modules	`PlcProfile::MelsecQ`	Public Q profile. Currently grouped with the Q/L command-device layout used by the existing Q/L encoder path.
`melsec:lcpu`	MELSEC-L	MELSEC-L serial modules	`PlcProfile::MelsecL`	Public L profile using the Q/L-compatible serial MC request shape. Keep it separate from `melsec:qcpu` for target-family evidence.
`melsec:qna`	MELSEC QnA	MELSEC QnA-compatible targets	`PlcProfile::MelsecQnA`	QnA command-family branch. Current implementation groups the shared QnA/AnA/AnU command-family behavior where the codec has no separate rule.
`melsec:ana-anu`	MELSEC AnA/AnU	MELSEC AnA / AnU-compatible targets	`PlcProfile::MelsecAnAAnU`	Public AnA/AnU profile. Currently shares the QnA-family internal branch until a manual-backed or measured difference is added.
`melsec:a`	MELSEC-A	MELSEC-A-compatible targets	`PlcProfile::MelsecA`	A-series command-family branch. A-only paths such as ER/EW extended file-register commands require this profile.

SLMP name alignment

The common PLC-family names intentionally match the SLMP libraries. Profiles that exist only in one protocol family are listed as not applicable.

PLC family	Serial MC profile	SLMP profile
MELSEC iQ-R	`melsec:iq-r`	`melsec:iq-r`
MELSEC iQ-L	`melsec:iq-l`	`melsec:iq-l`
MELSEC iQ-F / FX5	`melsec:iq-f`	`melsec:iq-f`
MELSEC-Q CPU	`melsec:qcpu`	`melsec:qcpu`
MELSEC-L CPU	`melsec:lcpu`	`melsec:lcpu`
MELSEC QnU	Not applicable	`melsec:qnu`
MELSEC QnUDV	Not applicable	`melsec:qnudv`
MELSEC MX-F	Not applicable	`melsec:mx-f`
MELSEC MX-R	Not applicable	`melsec:mx-r`
MELSEC QnA	`melsec:qna`	Not applicable
MELSEC AnA / AnU	`melsec:ana-anu`	Not applicable
MELSEC-A	`melsec:a`	Not applicable

How to select

auto protocol = mcprotocol::serial::highlevel::make_c4_ascii_format4_protocol(
    mcprotocol::serial::PlcProfile::MelsecQ,
    mcprotocol::serial::SumCheckMode::Disabled,
    mcprotocol::serial::RouteConfig {mcprotocol::serial::HostStationRoute {}});

For a custom C4 Binary session, use the tagged factory and pass every active selector:

auto protocol = mcprotocol::serial::ProtocolConfig::c4_binary(
    mcprotocol::serial::PlcProfile::MelsecQ,
    mcprotocol::serial::SumCheckMode::Enabled,
    mcprotocol::serial::RouteConfig {mcprotocol::serial::HostStationRoute {}});

Use the display-name helper only for UI labels:

const auto profile = mcprotocol::serial::PlcProfile::MelsecQ;
const char* saved_name = mcprotocol::serial::plc_profile_name(profile); // "melsec:qcpu"
const char* label = mcprotocol::serial::plc_profile_display_name(profile); // "MELSEC-Q"

PlcProfile::Unspecified and unknown enum values are configuration errors. Public protocol factories require a profile argument and every encode/client boundary rejects a noncanonical value before transport is opened or request bytes are produced.

Profile-specific cautions

Canonical profile	Caution
`melsec:iq-r`	Use for iQ-R serial-module routes. Some command behavior remains target/module dependent.
`melsec:iq-l`	Kept separate from iQ-R because iQ-L serial-module behavior is Q/L-subcommand based even when CPU-side SLMP looks iQ-R-like. Do not use the long timer/counter family, `LZ`, `RD`, or `Un\HG` with this profile.
`melsec:iq-f`	Use for FX5/iQ-F serial paths. `V`, `ZR`, `DX`, `DY`, long timer/retentive-timer families, `Un\HG`, `Jn\...`, monitor, host-buffer, and module-buffer helper routes are not part of this profile.
`melsec:qcpu`	Use for MELSEC-Q serial paths. The current implementation shares the Q/L request-shape branch but keeps Q as a separate public profile.
`melsec:lcpu`	Use for MELSEC-L serial paths. The current implementation shares the Q/L request-shape branch but keeps L as a separate public profile.
`melsec:qna`	Select only when the target should use QnA-style command selection.
`melsec:ana-anu`	Select only when the target should use AnA/AnU command-family selection.
`melsec:a`	Select for A-series-compatible targets; extended file-register ER/EW commands require this profile.

The profile does not replace serial settings. Baud rate, parity, stop bits, frame type, sum-check behavior, and station number still have to match the PLC serial module. Select sum-check explicitly with SumCheckMode::Enabled or SumCheckMode::Disabled; a named frame preset does not infer it.