DioWriteProgramCounter

Applies To

GC5050, GX5050, GX5055, GX5150, GX5280, GX5290, GX5290e, GX5295

Purpose

Writes a new value to the program counter.

Syntax

DioWriteProgramCounter (nMasterHandle, dwCounter, pnStatus)

Parameters

Name	Type	Comments
nMasterHandle	SHORT	Master or File board handle.
dwCounter	DWORD	Program counter value.
pnStatus	PSHORT	Returned status: 0 on success, negative number on failure.

Comments

GC5050/GX5050:

Sets the address of the input, output and control memories. The program counter may be changed only by a control memory command in the RUN state, or by calling a function that resets the program counter to 0, such as DioReset, DioSaveFile, etc. The control memory commands that change the value of the program counter are JUMP, LOOP, CALL and RETURN.

GX5055:

Sets the address of the input, output, direction, valid data and control memories. The program counter may be changed only by a control memory command in the RUN state, or by calling a function that resets the program counter to 0, such as DioReset, DioSaveFile, etc. The control memory commands that change the value of the program counter are JUMP, LOOP, CALL and RETURN.

GX5150:

Sets the address of the I/O and control memories. The program counter may be changed only by a control memory command in the RUN state, or by calling a function that resets the program counter to 0, such as DioReset, DioSaveFile, etc. The control memory commands that change the value of the program counter are JUMP, LOOP, CALL and RETURN.

GX5280/ GX5290/GX5290e/GX5295:

GX5280: Sets the address of the I/O memory.

GX5290/GX5290e/GX5295: Sets the address of the I/O and direction memories. The program counter may be changed only by a control memory command in the RUN state, or by calling a function that resets the program counter to 0, such as DioReset, DioSaveFile, etc.

When the number of active channels is less than 32, the program counter value will be rounded to be on a 32 channels boundaries. E.g. if the I/O configuration was set to 16 channels and the program counter value was set to 1025 the value will be rounded to 1024.

Note: when reading back the program counter value it will correspond to the actual active number of channels as follows:

Number of Active Channels	Program Counter Range
32	GX5281: 0 to 32M GX5282: 0 to 64M GX5283: 0 to 128M GX5291/GX5291e: 0 to 32M GX5292/GX5292e: 0 to 64M GX5293/GX5293e: 0 to 64M GX5295: 0 to 64M
16	GX5281: 0 to 64M GX5282: 0 to 128M GX5283: 0 to 256M GX5291/GX5291e: 0 to 64M GX5292/GX5292e: 0 to 128M GX5293/GX5293e: 0 to 128M GX5295: 0 to 128M
8	GX5281: 0 to 128M GX5282: 0 to 256M GX5283: 0 to 512M GX5291/GX5291e: 0 to 128M GX5292/GX5292e: 0 to 256M GX5293/GX5293e: 0 to 256M GX5295: 0 to 256M
4	GX5281: 0 to 256M GX5282: 0 to 512M GX5283: 0 to 1G GX5291/GX5291e: 0 to 256M GX5292/GX5292e: 0 to 512M GX5293/GX5293e: 0 to 512M GX5295: 0 to 512M
2	GX5281: 0 to 512M GX5282: 0 to 1G GX5283: 0 to 2G GX5291/GX5291e: 0 to 512M GX5292/GX5292e: 0 to 1G GX5293/GX5293e: 0 to 1G GX5295: 0 to 1G
1	GX5281: 0 to 1G GX5282: 0 to 2G GX5283: 0 to 4G GX5291/GX5291e: 0 to 1G GX5292/GX5292e: 0 to 2G GX5293/GX5293e: 0 to 2G GX5295: 0 to 2G

Example

The following example writes the value 1024 to the program counter and then verifies the setting by calling DioReadProgramCounter:

SHORT nStatus;

DWORD dwAddress;

DioWriteProgramCounter (nHandle, 1024, &nStatus);

DioReadProgramCounter (nHandle, &dwAddress, &nStatus);