net.solarnetwork.io.modbus.rtu.RtuModbusMessage Maven / Gradle / Ivy
/* ==================================================================
* RtuModbusMessage.java - 1/12/2022 2:53:32 pm
*
* Copyright 2022 SolarNetwork.net Dev Team
*
* 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307 USA
* ==================================================================
*/
package net.solarnetwork.io.modbus.rtu;
import net.solarnetwork.io.modbus.ModbusMessage;
import net.solarnetwork.io.modbus.ModbusValidationException;
/**
* RTU encapsulated Modbus message API.
*
* @author matt
* @version 1.0
*/
public interface RtuModbusMessage extends ModbusMessage {
/**
* A {@link ModbusValidationException} message template.
*
*
* The message accepts two short values: the provided CRC and the computed
* CRC.
*
*/
String CRC_MISMATCH_VALIDATION_MESSAGE = "CRC mismatch: got 0x%X but computed 0x%X from message data.";
/**
* Get a message creation date.
*
* @return the message creation date
*/
long getTimestamp();
/**
* Get the 16-bit cyclic redundancy check value presented in the RTU message
* frame.
*
* @return the provided CRC value
*/
short getCrc();
/**
* Compute the 16-bit cyclic redundancy check value from the message data.
*
*
* If the {@link #getCrc()} and this value differ, the message should be
* considered corrupted.
*
*
* @return the computed CRC value
*/
short computeCrc();
/**
* Test if the provided and computed CRC values match.
*
* @return {@literal true} if {@link #getCrc()} and {@link #computeCrc()}
* return the same value
*/
default boolean isCrcValid() {
final short provided = getCrc();
final short computed = computeCrc();
return (provided == computed);
}
@Override
default RtuModbusMessage validate() throws ModbusValidationException {
final short provided = getCrc();
final short computed = computeCrc();
if ( provided != computed ) {
throw new ModbusValidationException(
String.format(CRC_MISMATCH_VALIDATION_MESSAGE, provided, computed));
}
return this;
}
}