Modbus TCP module with both read and write

otherio/lib/rt/src/os_linux/rt_io_m_mb_modulereadwrite.c

+/* 
+ * Proview   Open Source Process Control.
+ * Copyright (C) 2005-2011 SSAB Oxelosund AB.
+ *
+ * This file is part of Proview.
+ *
+ * This program is free software; you can redistribute it and/or 
+ * modify it under the terms of the GNU General Public License as 
+ * published by the Free Software Foundation, either version 2 of 
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful 
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of 
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License 
+ * along with Proview. If not, see <http://www.gnu.org/licenses/>
+ *
+ * Linking Proview statically or dynamically with other modules is
+ * making a combined work based on Proview. Thus, the terms and 
+ * conditions of the GNU General Public License cover the whole 
+ * combination.
+ *
+ * In addition, as a special exception, the copyright holders of
+ * Proview give you permission to, from the build function in the
+ * Proview Configurator, combine Proview with modules generated by the
+ * Proview PLC Editor to a PLC program, regardless of the license
+ * terms of these modules. You may copy and distribute the resulting
+ * combined work under the terms of your choice, provided that every 
+ * copy of the combined work is accompanied by a complete copy of 
+ * the source code of Proview (the version used to produce the 
+ * combined work), being distributed under the terms of the GNU 
+ * General Public License plus this exception.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <math.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/socket.h>
+
+
+
+#include "pwr.h"
+#include "pwr_baseclasses.h"
+#include "pwr_basecomponentclasses.h"
+#include "pwr_otherioclasses.h"
+#include "rt_io_base.h"
+#include "rt_io_msg.h"
+#include "rt_errh.h"
+#include "rt_io_bus.h"
+#include "rt_mb_msg.h"
+
+#include "rt_io_mb_locals.h"
+
+/*----------------------------------------------------------------------------*\
+   Init method for the Modbus module
+\*----------------------------------------------------------------------------*/
+static pwr_tStatus IoCardInit (
+  io_tCtx	ctx,
+  io_sAgent	*ap,
+  io_sRack	*rp,
+  io_sCard	*cp
+) 
+{
+  io_sCardLocal *local;
+  pwr_sClass_Modbus_ModuleReadWrite *op;
+  int i;
+
+  op = (pwr_sClass_Modbus_ModuleReadWrite *) cp->op;
+  local = (io_sCardLocal *) cp->Local;
+  
+  for (i = 0; i < IO_MAXCHAN; i++) {
+    local->msg[0].scancount[i] = 0;
+    local->msg[1].scancount[i] = 0;
+  }
+
+  op->Read.Status = pwr_eModbusModule_StatusEnum_StatusUnknown;
+  op->Write.Status = pwr_eModbusModule_StatusEnum_StatusUnknown;
+
+  return IO__SUCCESS;
+}
+
+
+/*----------------------------------------------------------------------------*\
+   Read method for the Pb module
+\*----------------------------------------------------------------------------*/
+static pwr_tStatus IoCardRead (
+  io_tCtx	ctx,
+  io_sAgent	*ap,
+  io_sRack	*rp,
+  io_sCard	*cp
+) 
+{
+  io_sCardLocal *local;
+  pwr_sClass_Modbus_ModuleReadWrite *op;
+  pwr_sClass_Modbus_TCP_Slave *slave;
+
+  op = (pwr_sClass_Modbus_ModuleReadWrite *) cp->op;
+  local = (io_sCardLocal *) cp->Local;
+  slave = (pwr_sClass_Modbus_TCP_Slave *) rp->op;
+
+  if ( op->Read.ScanInterval > 1) {
+    local->msg[0].has_read_method = 1;
+    if ( local->msg[0].interval_cnt != 0) {
+      local->msg[0].interval_cnt++;
+      if ( local->msg[0].interval_cnt >= op->Read.ScanInterval)
+        local->msg[0].interval_cnt = 0;
+      return IO__SUCCESS;
+    }
+    local->msg[0].interval_cnt++;
+  }
+
+  if (slave->Status == MB__NORMAL) { 
+    io_bus_card_read(ctx, rp, cp, slave->Inputs, NULL,  pwr_eByteOrderingEnum_BigEndian, pwr_eFloatRepEnum_FloatIntel);  
+  }
+  return IO__SUCCESS;
+}
+
+
+/*----------------------------------------------------------------------------*\
+   Write method for the Pb module
+\*----------------------------------------------------------------------------*/
+static pwr_tStatus IoCardWrite (
+  io_tCtx	ctx,
+  io_sAgent	*ap,
+  io_sRack	*rp,
+  io_sCard	*cp
+) 
+{
+  io_sCardLocal *local;
+  pwr_sClass_Modbus_ModuleReadWrite *op;
+  
+  pwr_sClass_Modbus_TCP_Slave *slave;
+
+  op = (pwr_sClass_Modbus_ModuleReadWrite *) cp->op;
+  local = (io_sCardLocal *) cp->Local;
+  slave = (pwr_sClass_Modbus_TCP_Slave *) rp->op;
+  
+  if ( op->Write.ScanInterval > 1) {
+    if ( !local->msg[1].has_read_method) {
+      if ( local->msg[1].interval_cnt != 0) {
+	local->msg[1].interval_cnt++;
+	if ( local->msg[1].interval_cnt >= op->Write.ScanInterval)
+	  local->msg[1].interval_cnt = 0;
+	return IO__SUCCESS;
+      }
+      local->msg[1].interval_cnt++;
+    }
+    else if ( local->msg[1].interval_cnt != 1)
+      return IO__SUCCESS;
+  }
+
+  if (slave->Status == MB__NORMAL) { 
+    io_bus_card_write(ctx, cp, slave->Outputs, pwr_eByteOrderingEnum_BigEndian, pwr_eFloatRepEnum_FloatIntel);
+  }
+//  printf("Method Modbus_Module-IoCardWrite\n");
+  return IO__SUCCESS;
+}
+
+
+/*----------------------------------------------------------------------------*\
+  Every method to be exported to the workbench should be registred here.
+\*----------------------------------------------------------------------------*/
+
+pwr_dExport pwr_BindIoMethods(Modbus_ModuleReadWrite) = {
+  pwr_BindIoMethod(IoCardInit),
+  pwr_BindIoMethod(IoCardRead),
+  pwr_BindIoMethod(IoCardWrite),
+  pwr_NullMethod
+};
+