The data type to read from or write to is usually implied by the address. If it is not, the strings below may be appended to the address (without spaces) to force the data to be interpreted as a specific type:
|
Suffix |
Meaning |
|
/ABFloat |
Allen-Bradley PLC/3 Floating Point (4 bytes) (Used for Allen-Bradley exclusively) |
|
/AB5Float |
Allen-Bradley PLC/5 Floating Point (4 bytes) (Used for Allen-Bradley exclusively) |
|
/BCD2 |
2-digit (1 byte) Binary Coded Decimal |
|
/BCD3 |
3-digit (2 bytes – lowest 12 bits) Binary Coded Decimal |
|
/BCD4 |
4-digit (2 bytes) Binary Coded Decimal |
|
/Bit |
Attempts to convert the value to a single bit. The bit number used is always 0. (ex: 40001/Bit) |
|
/Double |
IEEE Double Precision Floating Point (8 bytes) |
|
/Float |
IEEE Single Precision Floating Point (4 bytes) |
|
/SByte |
Signed Byte |
|
/SDWord |
Signed 32-bit Integer |
|
/SWord |
Signed 16-bit Integer |
|
/UByte |
Unsigned Byte |
|
/UDWord |
Unsigned 32-bit Integer |
|
/UWord |
Unsigned 16-bit Integer |
For example:
40001/UDWord
Each I/O device uses a different addressing scheme. These addressing schemes are referenced below.
• Allen-Bradley Driver Addressing;
• Omron Addressing; and
• OPC Client Driver Addressing.
The sections that follow identify the VTS driver tag types and their properties.