Software for 1746 I/O

Publication 1747-6.5.3 June 1998
Chapter 4
Using the API Structures
Introduction This chapter describes the structures the API uses. These structures are declared in
ocapi.h.
API Structures
Structure Name: Syntax:
DII_CFG
Passed to OC_ConfigureDII.
Configures a discrete input
interrupt for a module.
typedef struct tagDII_CFG
BYTE SlotNum; /* slot number */
BYTE IOIncludeMask; /* declare which Discrete Inputs can cause interrupts */
BYTE IOEdgeType; /* select required transition of each discrete input */
WORD PresetCount; /* set the number of transitions required to cause interrupt */
} DII_CFG;
FORCEDATA
Passed to OC_SetForces.
Configures input and output
forces.
typedef struct tagFORCEDATA
{
BYTE SlotNum; /* slot number */
WORD WordOffset; /* offset to word to force */
BYTE IOType; /* selects force inputs or outputs */
WORD ForceMask; /* bits set to 1 are forced, 0 removes forces */
WORD ForceVal; /* selects force state of bits set to 1 in ForceMask */
} FORCEDATA;
MSGBUF
Returned by OC_PollScanner.
MsgID identifies the message
type. Type-specific data is
contained in MsgData[ ].
#define OCMSGDATASIZE4 /* number of bytes of message data */
typedef struct tagMSGBUF
{
BYTE MsgID; /* Message type */
BYTE MsgData[OCMSGDATASIZE]; /* Type-specific data */
} MSGBUF;
OCEXTERR
Returned by
OC_GetExtendedError. I/O error
report from scanner.
#define OCERRDATASIZE3 /* number of bytes of error data */
typedef struct tagOCEXTERR
{
BYTE ErrorCode; /* Extended error code */
BYTE SlotNum; /* Associated slot number */
BYTE ErrorData[OCERRDATASIZE];/* Error code data */
} OCEXTERR;
OCINIT
Passed to OC_InitScanner
function to specify dual port
RAM partition sizes for output
image, input image, and host
retentive data.
typedef struct tagOCINIT
{
WORD OutputImageSize; /* size in bytes */
WORD InputImageSize; /* size in bytes */
WORD HostRetentiveDataSize;/* size in bytes */
} OCINIT;
OCIOCFG
Used by
OC_CreateIOConfiguration,
OC_GetIOConfiguration, and
OC_DownloadIOConfiguration.
Configuration information for a
system. 1, 2, or 3 racks may be
configured for up to 30 I/O
modules. (Slot 0 is reserved for
the 1746 I/O PCI Interface.)
typedef struct tagOCIOCFG
{
BYTE Rack1Size; /* number of slots in Rack 1 */
BYTE Rack2Size; /* number of slots in Rack 2 */
BYTE Rack3Size; /* number of slots in Rack 3 */
OCSLOTCFGSlotCfg[OCMAXSLOT];/* configuration for each slot */
} OCIOCFG;