DC Relay C Demo

DC Relay C Demo

// *********************************************************************
// FILE NAME:   dcrelay.c
// ---------------------------------------------------------------------
// AUTHOR:      DAVID J. SIU
//              BEN MORSE
// DATE:        5/6/2009
// VERSION:     1.1
// ---------------------------------------------------------------------
// This is the driver code for the DC Relay Module.
// This code:
//     -Initializes the DC Relay Module.
//     -Turns a relay on or off.
//     -Returns the state of the relays.
// ---------------------------------------------------------------------
// Important user words:
// Init_DC_Relay:         Initializes the DC Relay Module.
// Control_DC_Relay:      Turns the specified relay on or off.
// Read_DC_Relay_Status:  Returns the state of the relays.
// WDCM_MODULE_NUM        this constant MUST match hardware jumper settings!
// ---------------------------------------------------------------------
// Notes:
// RELAYS ARE ACTIVE LOW!  WRITING A 1 TO THE RELAY TURNS IT OFF WHILE
// WRITING A 0 TO THE RELAY TURNS IT ON!
//
// Disclaimer: THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT
//             ANY WARRANTIES OR REPRESENTATIONS EXPRESS OR IMPLIED,
//             INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES
//             OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
//
// *********************************************************************
 
 
#include <mosaic\allqed.h>         // Include QED header files
 
#ifndef __GNUC__
#include "../../libraries/include/io_access.h"
#include "../../libraries/include/io_access.c"
#endif
 
// NOTE: YOU MUST MAKE SURE THAT THIS CONSTANT CORRESPONDS TO YOUR MODULE SELECT JUMPERS!
// For example, to access the Wildcard at address 4:
//    remove both module select jumper caps and mount the card on Wildcard Module Bus 1
#define WDCM_MODULE_NUM 4
// Note: if you are using a QScreen or Handheld, accessing a wildcard at module address 0
// is not allowed; this module address is reserved for the GUI on the QScreen and Handheld.
 
 
// Relays are active low (i.e. writing a 0 to the relay turns it on).
#define RELAY_ON                0
#define RELAY_OFF               1
 
#define RELAY_CONTROL_LINES     1
#define DIRECTION_OFFSET      0x05
#define RELAY_CONTROL_OFFSET  0x00
#define ALL_RELAYS          0xF
 
_Q void Init_DC_Relay ( uchar module_number ) // Valid module numbers are 0-7
// Initializes the DC Relay Module by configuring the DC relay control lines
// of the CPLD to outputs.  The module number depends on the module select
// jumpers.  See Table 1 for the jumper settings and associated addresses.
{
  // Turn all relays off before initializing control lines to outputs.
  // Relays are active low (i.e. writing a 0 to the relay turns it on).
  IOStoreChar( ALL_RELAYS, RELAY_CONTROL_OFFSET, module_number );
 
  IOStoreChar( RELAY_CONTROL_LINES, DIRECTION_OFFSET, module_number );
}
 
_Q void Control_DC_Relay ( uchar module_number, uchar relay_num, uchar state )
// Sets the relay number to the appropriate state (on or off).
// Valid relay numbers are 0-2.  Valid module numbers are 0-7.
{
  if(state) // turn relay off
  {
    state = state << relay_num;
    IOSetBits( state, RELAY_CONTROL_OFFSET, module_number );
  }
  else  // turn relay on
  {
    state = 1 << relay_num;
    IOClearBits ( state, RELAY_CONTROL_OFFSET, module_number );
  }
}
 
_Q uchar Read_DC_Relay_Status ( uchar module_number )
// Reads the current state of the opto isolated DC Relays.  Valid module numbers are 0-7.
// Returns a character whose three least significant bits represents the
// three relays.  For example, if 1 is returned (001 in binary), then Relay 0
// is off and the other relays are on.  If 6 is returned (110 in binary),
// then relays 1 and 2 are off and 0 is on.  The five most significant bits
// do not matter.
{
  char dc_relay_status;
 
  dc_relay_status = IOFetchChar( RELAY_CONTROL_OFFSET, module_number );
 
  return( dc_relay_status );
}
 
// main() function for C example showing control of
// Crydom Solid State Relays (SSRS)
int main ( void )
{
  Init_DC_Relay( WDCM_MODULE_NUM );
 
  printf("\npress enter to turn on the first relay.\n");
  Key();
  Control_DC_Relay( WDCM_MODULE_NUM, 0, RELAY_ON );    // turn on 1st relay
  printf("press enter to turn on the second relay.\n");
  Key();
  Control_DC_Relay( WDCM_MODULE_NUM, 1, RELAY_ON );    // turn on 2nd relay
  printf("press enter to turn on the third relay.\n");
  Key();
  Control_DC_Relay( WDCM_MODULE_NUM, 2, RELAY_ON );    // turn on 3rd relay
 
  printf("press enter to turn off the first relay.\n");
  Key();
  Control_DC_Relay( WDCM_MODULE_NUM, 0, RELAY_OFF );    // turn off 1st relay
  printf("press enter to turn off the second relay.\n");
  Key();
  Control_DC_Relay( WDCM_MODULE_NUM, 1, RELAY_OFF );    // turn off 2nd relay
  printf("press enter to turn off the third relay.\n");
  Key();
  Control_DC_Relay( WDCM_MODULE_NUM, 2, RELAY_OFF );    // turn off 3rd relay
 
  printf("press enter to turn on all three relays.\n");
  Key();
  IOClearBits( ALL_RELAYS, RELAY_CONTROL_OFFSET, WDCM_MODULE_NUM );
  printf("press enter to turn off all three relays.\n");
  Key();
  IOSetBits( ALL_RELAYS,  RELAY_CONTROL_OFFSET, WDCM_MODULE_NUM );
 
  return 0;
}