Supported registers

This page lists the public device families used by the low-level and high-level APIs. Actual availability still depends on your PLC model, profile, and project settings.

Bit device families

Family	Meaning	Notes
SM	Special relay	Decimal numbering.
X	Input	Profile-aware string parsing is required; iQ-F uses octal, other supported profiles use hexadecimal.
Y	Output	Profile-aware string parsing is required; iQ-F uses octal, other supported profiles use hexadecimal.
M	Internal relay	Decimal numbering.
L	Latch relay	Decimal numbering.
F	Annunciator	Low-level helper name is slmp::dev::FDevice.
V	Edge relay	Decimal numbering.
B	Link relay	Hexadecimal numbering.
TS	Timer contact	Decimal numbering.
TC	Timer coil	Decimal numbering.
LTS	Long timer contact	Long timer state family.
LTC	Long timer coil	Long timer state family.
STS	Retentive timer contact	Decimal numbering.
STC	Retentive timer coil	Decimal numbering.
LSTS	Long retentive timer contact	Long retentive timer state family.
LSTC	Long retentive timer coil	Long retentive timer state family.
CS	Counter contact	Decimal numbering.
CC	Counter coil	Decimal numbering.
LCS	Long counter contact	Long counter state family.
LCC	Long counter coil	Long counter state family.
SB	Link special relay	Hexadecimal numbering.
DX	Direct input	Not valid for slmp::highlevel::PlcProfile::IqF.
DY	Direct output	Not valid for slmp::highlevel::PlcProfile::IqF.

Word device families

Family	Meaning	Notes
SD	Special register	Decimal numbering.
D	Data register	Common 16-bit, 32-bit, and float storage family.
W	Link register	Hexadecimal numbering.
TN	Timer current value	Decimal numbering.
LTN	Long timer current value	Use slmp::highlevel::ValueType::U32 or slmp::highlevel::ValueType::S32.
STN	Retentive timer current value	Decimal numbering.
LSTN	Long retentive timer current value	Use slmp::highlevel::ValueType::U32 or slmp::highlevel::ValueType::S32.
CN	Counter current value	Decimal numbering.
LCN	Long counter current value	Use slmp::highlevel::ValueType::U32 or slmp::highlevel::ValueType::S32.
SW	Link special register	Hexadecimal numbering.
Z	Index register	Decimal numbering.
LZ	Long index register	Use slmp::highlevel::ValueType::U32 or slmp::highlevel::ValueType::S32.
R	File register	Decimal numbering.
ZR	Continuous file register	Decimal numbering.
RD	Refresh data register	Decimal numbering.

Value types

Type	C++ name	Size	Meaning
BIT	slmp::highlevel::ValueType::Bit	1 logical bit	Boolean value in slmp::highlevel::Value::bit.
U	slmp::highlevel::ValueType::U16	16 bits	Unsigned word in slmp::highlevel::Value::u16.
S	slmp::highlevel::ValueType::S16	16 bits	Signed word in slmp::highlevel::Value::s16.
D	slmp::highlevel::ValueType::U32	32 bits	Unsigned double word in slmp::highlevel::Value::u32.
L	slmp::highlevel::ValueType::S32	32 bits	Signed double word in slmp::highlevel::Value::s32.
F	slmp::highlevel::ValueType::Float32	32 bits	IEEE-754 float in slmp::highlevel::Value::f32.

Addressing notes

Topic	Rule
Long families	LTN, LSTN, LCN, and LZ require U32 or S32; 16-bit access yields wrong data.
Module buffer memory	G and HG are not in the public high-level surface for normal direct device access. Use raw slmp::SlmpClient module-buffer APIs such as readWordsModuleBuf.
Step relay	S is not exposed publicly by the current headers.
Direct input/output	DX and DY are not valid for the iQ-F profile.
X and Y strings	Use profile-aware overloads; iQ-F uses octal notation while other supported profiles use hexadecimal notation.
Bit-in-word	Use .n with n from 0 to F, for example D50.3.

PLC profiles

See PLC profiles for profile identifiers, frame types, compatibility modes, and profile-specific cautions.