Rockwell Automation 1747-PCIS API Software - Open Controller - Manual (Page 115)

Publication 1747-UM002A-US-P - June 2000
Library of Routines 6-55
OC_SetForces OC_SetForces installs and removes input and output forces to
the scanner.
Syntax:
int OC_SetForces(HANDLE handle, FORCEDATA
* forcedata)
Parameters:
Description:
If the result of OC_SetForces removes all I/O forces, the scanner
disables forces. If any I/O forces are later installed, OC_EnableForces
must be called to re-enable forces.
The FORCEDATA structure is defined as:
typedef struct tagFORCEDATA {
BYTE SlotNum; /* Slot Number of local I/O or
1747-SN module (1-30)*/
WORD WordOffset; /* Word Offset in I/O image */
BYTE IOType; /* Selects Input or Output Image */
WORD ForceMask; /* Install/Remove bitmask */
WORD ForceVal; /* Install value bitmask */
} FORCEDATA;
Parameter: Description:
handle Must be a valid handle returned from OC_OpenScanner
forcedata Defines the inputs and outputs to force.
This value: Means:
SlotNum
WordOffset SlotNum and WordOffset select the word of I/O that contains the
bits to be forced
IOType
IOType
must be FORCE_INPUTS or FORCE_OUTPUTS
ForceMask
ForceVal All 16 bits of the word are installed/removed according to
ForceMask and ForceVal
Each bit in ForceMask that is set to 0 will have its force removed.
Each bit in
ForceMask
that is set to 1 will have its force installed.
For each bit that has its force installed, the corresponding bit in
ForceVal
determines the state of the force. For bits that have their
force removed, the corresponding bit in ForceVal is ignored.