Rockwell Automation 1747-PCIS API Software - Open Controller - Manual (Page 56)

Publication 1747-UM002A-US-P - June 2000
5-2 Configuring I/O Modules
SlotCfg contains information about each slot in the racks. The 1746
I/O PCI Interface supports as many as 31 slots, numbered 0 to 30. Slot
0 is the adapter slot (left slot of rack 1) and is invalid for scanner
functions. Each slot is described by the structure
OCSLOTCFG :
struct {
BYTE mix; /* Module I/O Mix value */
BYTE type; /* Module Type */
BYTE InputSize; /* number of inputs in bytes */
BYTE OutputSize; /* number of outputs in bytes */
WORD M0Size; /* size of M0 file in words */
WORD M1Size; /* size of M1 file in words */
WORD GSize; /* size of G file in words */
WORD *GData; /* pointer to array of length GSize
words */
char *Name; /* pointer to module name string */
} OCSLOTCFG;
You can specify a module by name or by mix and type. You only
specify G data if the module uses G files (such as the 1747-SN). If the
Name pointer is NULL, OC_CreateIOConfiguration uses mix and type
to identify the module. See page 4 for the mix and type values.
OC_CreateIOConfiguration supplies the InputSize , OutputSize ,
M0Size , M1Size , Gsize , and Name fields.
If Name points to a string containing a valid module name, the module
name identifies the module. OC_CreateIOConfiguration supplies the
mix , type , InputSize , OutputSize , M0Size , M1Size , and Gsize
fields.
Initialize empty slots and slot 0 with a mix value of 0xFF and a type
value of 0xFF.
If the module is not in the internal database,
OC_CreateIOConfiguration doesn’t alter the OCSLOTCFG.
To support modules not included in the internal database of modules,
the host application can initialize the
mix , type , InputSize ,
OutputSize , M0Size , M1Size , and GSize before downloading the
I/O configuration to the scanner. See the I/O module’s user manual to
determine the proper configuration information.
After the OC_CreateIOConfiguration and OCGetIOConfiguration
functions return, the I/O configuration structure must be checked for
installed modules with G files. If the
Gsize field of a non-empty slot
configuration is not zero, then the module contains a G file. If the
module contains a G file, initialize
GData to point to an array of
Gsize words to be loaded into the module during scanner
configuration. See the I/O module’s user manual to determine the
proper G file data.