AVEVA™ Communication Drivers

Item reference syntax

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Item reference syntax

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Last UpdatedJul 29, 2024
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Item references in this Communication Driver use the following syntax.

For digital registers (i.e., register types X, Y, C), use the following syntax:

<register type><address>

The following syntax diagram shows all of the possible options:

{ X | Y | C }address

For example: X1
For analog registers (i.e., register types V, K, TCP, TCC, WX, WY), use either of the following syntaxes:

<register type><address>.[bit]

For example: V1.2

<register type><address><data type>

For example: V1D

The following syntax diagram shows all of the possible options:

{ V | K | TCP | TCC | WX | WY }address{ | .bit | F | .Step | D | S | U | ST<length> | STS<length> }

Register type

The type of memory register on the target device:

Type	Description
X	Discrete Input
Y	Discrete Output
C	Control Relay
V	Variable Memory
K	Constant Memory
TCP	Timer/ Count Preset Memory
TCC	Timer/ Count Count Memory
WX	Word Input Memory
WY	Word Output Memory
STW	System Status Memory
DCC	Drum Current Count Memory
DCP	Drum Count Preset Memory
DSP	Drum Step Preset Memory

Address

The address of the memory register on the target device.

Bit

The bit number (1 to 16) to be accessed in the memory register.

This parameter is optional; if no bit is specified, the entire 16-bit Word is used by default.

Data type

The data type of the memory register: The data type is specified as a suffix in the item syntax. The TI500 Communication Driver supports the following data types.

DataType	Suffix	Description
Bit(Boolean)	.Bit	Single bit. Bit 1 is the most significant bit. Bit 16 is the least significant bit.
Float	F	Floating point or real number (32-bit).
DWord	D	Unsigned, 32-bit decimal value. Bit 1 is the most significant bit and Bit 32 is the least significant bit.
Integer	S	Signed 16-bit value. Note: If the S data type is is used, then registers can receive signed values even if the channel selector property is set to unsigned.
Integer	U	Unsigned 16-bit value. Note: If the U data type is used, then registers can receive unsigned values even if the channel selector property is set to signed.
Integer	DS	Signed 32-bit value. Note: If the DS data type is is used, then registers can receive signed values even if the channel selector property is set to unsigned.
Integer	DU	Unsigned 32-bit value. Note: If the DU data type is used, then registers can receive unsigned values even if the channel selector property is set to signed.
String	ST<length>	String. <length> denotes the number of characters in the string. Every word in PLC contains two characters; the first byte in the word is the first character, and the second byte is the second character.
String	STS<length>	String with byte swap. <length> denotes the number of characters in the string. Every word in PLC contains two characters. Byte swap means that the first byte in the word is the second character, and the second byte is the first character.

This parameter is optional; if no type is specified, it is considered to be Word (i.e., signed, 16-bit) by default.

Suffix data types

All registers support the suffix ST<length> and STS<length> except X, Y, and C and DCP.
The maximum string length that can be specified depends on the register it is used with.
The length is a required parameter when using ST or STS.
In the Channel Selector screen, if you select the Serial/Ethernet field as Serial (NITP) or Serial (TBP), the String data types ST and STS are not supported.
The DCP register requires a .Step suffix. It does not support any other suffixes.

AVEVA™ Communication Drivers