38.9.4.1 Function for read/write

Direct read API of single handle system

• Bit Data

INT WINAPI ReadDeviceBit(LPCSTR sNodeName,LPCSTR sDeviceName,WORD* owData,WORD wCount);

• 16 bit data

INT WINAPI ReadDevice16(LPCSTR sNodeName,LPCSTR sDeviceName,WORD* owData,WORD wCount);

• 32 bit data

INT WINAPI ReadDevice32(LPCSTR sNodeName,LPCSTR sDeviceName,DWORD* odwData,WORD wCount);

• 16-bit BCD data

INT WINAPI ReadDeviceBCD16(LPCSTR sNodeName,LPCSTR sDeviceName,WORD* owData,WORD wCount);

• 32-bit BCD data

INT WINAPI ReadDeviceBCD32(LPCSTR sNodeName,LPCSTR sDeviceName,DWORD* odwData,WORD wCount);

• Single float number data

INT WINAPI ReadDeviceFloat(LPCSTR sNodeName,LPCSTR sDeviceName,FLOAT* oflData,WORD wCount);

• Double float number data

INT WINAPI ReadDeviceDouble(LPCSTR sNodeName,LPCSTR sDeviceName,DOUBLE* odbData,WORD wCount);

• Text data

INT WINAPI ReadDeviceStr(LPCSTR sNodeName,LPCSTR sDeviceName,LPSTR psData,WORD wCount);

• General data

INT WINAPI ReadDevice(LPCSTR sNodeName,LPCSTR sDeviceName,LPVOID pData,WORD wCount,WORD wAppKind);

• General data (Variant Type)

INT WINAPI ReadDeviceVariant(LPCSTR sNodeName,LPCSTR sDeviceName,LPVARIANT pData,WORD wCount,WORD wAppKind);

Single handle system API

• Bit Data

INT WINAPI WriteDeviceBit(LPCSTR sNodeName,LPCSTR sDeviceName,WORD* pwData,WORD wCount);

• 16 bit data

INT WINAPI WriteDevice16(LPCSTR sNodeName,LPCSTR sDeviceName,WORD* pwData,WORD wCount);

• 32 bit data

INT WINAPI WriteDevice32(LPCSTR sNodeName,LPCSTR sDeviceName,DWORD* pdwData,WORD wCount);

• 16-bit BCD data

INT WINAPI WriteDeviceBCD16(LPCSTR sNodeName,LPCSTR sDeviceName,WORD* pwData,WORD wCount);

• 32-bit BCD data

INT WINAPI WriteDeviceBCD32(LPCSTR sNodeName,LPCSTR sDeviceName,DWORD* pdwData,WORD wCount);

• Single float number data

INT WINAPI WriteDeviceFloat(LPCSTR sNodeName,LPCSTR sDeviceName,FLOAT* pflData,WORD wCount);

• Double float number data

INT WINAPI WriteDeviceDouble(LPCSTR sNodeName,LPCSTR sDeviceName,DOUBLE* pdbData,WORD wCount);

• Text data

INT WINAPI WriteDeviceStr(LPCSTR sNodeName,LPCSTR sDeviceName,LPCSTR psData,WORD wCount);

• General data

INT WINAPI WriteDevice(LPCSTR sNodeName,LPCSTR sDeviceName,LPVOID pData,WORD wCount,WORD wAppKind);

• General data (Variant Type)

INT WINAPI WriteDeviceVariant(LPCSTR sNodeName,LPCSTR sDeviceName,LPVARIANT pData,WORD wCount,WORD wAppKind);

Group Symbol Read API for Single Handle

• Group Symbol

INT WINAPI ReadSymbol(LPCSTR sNodeName,LPCSTR sSymbolName,LPVOID oReadBufferData);

• Group Symbol (Variant Type)

INT WINAPI ReadSymbolVariant(LPCSTR sNodeName,LPCSTR sSymbolName,LPVARIANT pData);

Group Symbol Write API for Single Handle

• Group Symbol

INT WINAPI WriteSymbol(LPCSTR sNodeName,LPCSTR sSymbolName,LPVOID pWriteBufferData);

• Group Symbol (Variant Type)

INT WINAPI WriteSymbolVariant(LPCSTR sNodeName,LPCSTR sSymbolName,LPVARIANT pData);

Argument

• sNodeName: The station name is fixed as "WinGP".

sDeviceName: Directly describes the symbol names and device addresses registered in GP-Pro EX.

• Example 1) Use a symbol
  "SWITCH1"

• Example 2) Directly specify the device address
  "M100"

The following table shows the data types that you can specify when using symbols in each function.

• pxxData: Pointer for read/write data

Defines the destination pointer for values that are read or values that are written. For each function, please define the corresponding data format pointer.

• wCount: Number of read/write data

For the Read/WriteDeviceStr function, the amount of text data is expressed in single-byte units. If the symbol refers to a 16-bit device, use two characters to specify the number. If it refers to a 32-bit device, use four characters.
The following table shows the maximum amount of read/write data.

• wAppKind: Data Type Value

To specify the Data Type Value, you can either directly specify the value or specify using a constant name. For more details, please refer to the following.
38.9.5.1 Data Type

Return value (NULL)

Normal end: 0

Problem: Error code

Supplementary

• When using Read/WriteDeviceBit function

pwData stores the same amount of data as in wCount starting from D0 bit.
For example, when wCount = 20

• Handling sequential multiple bit data

it is more efficient to read/write in 16/32 bits using Read/WriteDevice16 and Read/WriteDevice32 than using Read/WriteDeviceBit.
"*" contains undefined values Mask the value using an application program.

• When using Read/WriteDeviceBCD16/32 functions

Use these functions for handling data as BCD internally in the device/PLC. Note that data (pxxData content) sent to or received from the function is binary data, not BCD.
BCD conversion is run internally in the WinGP SDK. Cannot handle negative numbers.

• When using the text data function

For variables to receive text data, secure sufficient data space to receive the data.