B&B Electronics RS-232 Digital Relay I/O 232DRIO - Manual (Page 23)

232DRIO-0308 Manual 21
B&B Electronics -- PO Box 1040 -- Ottawa, IL 61350
PH (815) 433-5100 -- FAX (815) 433-5104
C/C++ (DEMO232.EXE and DEMO232.CPP)
DEMO232.CPP is a demonstration program for use with B&B
Electronics model 232DRIO module. Much of the work associated
with using COM ports in C/C++ has been made easier by including
the 232DRIO.LIB with this program.
Including
“232DRIO.H” in the pre-processor directive and
compiling your .cpp file as a project along with the 232DRIO.LIB file
will enable you to use the following functions in your program.
Important Note: For Borland C++, the compiler must be set
for large memory model for your program to compile properly.
Access this by the pulldown menu Options/Compiler/Code
Generation/ to change model size and click on ok.
#include”232DRIO.H”
void main ()
{
/* put your program here */
}
Read I/O States Command
states = bbDRIO_ReadIOLines(hComDev, int mode)
Mode is 1 if harsh environment is enabled or 0 if disabled. Returns
–1 if an error occurred.
Example 5.3 – Determining the status of Relay #1
If(states & 0x01) Æ True if Relay #1 is on
When the line is executed, states will contain a byte that can by
read by “ANDing” states with the appropriate mask.
Set Output States Command
bbDRIO_SetOutputLines(unsigned short hComDev,
unsigned char states, int mode)
Example 5.4 – Various ways to energized/de-energized Relay #1
1) A relay can be energized by “ORing” states with the
appropriate mask.
states |= 0x01 Æ Will energized Relay #1
2) A relay can be de-energized by “ANDing” with the
complement of the mask. (~mask)
states &= 0xFE Æ Will de-energized Relay #1
3) A relay can be switched by “Exclusive ORing” states with the
appropriate mask.
states ^= 0x01 Æ Will energized Relay #1 if it is de-
energized or vice versa