com.digitalpetri.modbus.codec.ModbusRequestEncoder.java Source code

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Here is the source code for com.digitalpetri.modbus.codec.ModbusRequestEncoder.java

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/*
 * Copyright 2016 Kevin Herron
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.digitalpetri.modbus.codec;

import com.digitalpetri.modbus.ModbusPdu;
import com.digitalpetri.modbus.requests.MaskWriteRegisterRequest;
import com.digitalpetri.modbus.requests.ReadCoilsRequest;
import com.digitalpetri.modbus.requests.ReadDiscreteInputsRequest;
import com.digitalpetri.modbus.requests.ReadHoldingRegistersRequest;
import com.digitalpetri.modbus.requests.ReadInputRegistersRequest;
import com.digitalpetri.modbus.requests.WriteMultipleCoilsRequest;
import com.digitalpetri.modbus.requests.WriteMultipleRegistersRequest;
import com.digitalpetri.modbus.requests.WriteSingleCoilRequest;
import com.digitalpetri.modbus.requests.WriteSingleRegisterRequest;
import io.netty.buffer.ByteBuf;
import io.netty.handler.codec.EncoderException;
import io.netty.util.ReferenceCountUtil;

public class ModbusRequestEncoder implements ModbusPduEncoder {

    @Override
    public ByteBuf encode(ModbusPdu modbusPdu, ByteBuf buffer) throws EncoderException {
        try {
            switch (modbusPdu.getFunctionCode()) {
            case ReadCoils:
                return encodeReadCoils((ReadCoilsRequest) modbusPdu, buffer);

            case ReadDiscreteInputs:
                return encodeReadDiscreteInputs((ReadDiscreteInputsRequest) modbusPdu, buffer);

            case ReadHoldingRegisters:
                return encodeReadHoldingRegisters((ReadHoldingRegistersRequest) modbusPdu, buffer);

            case ReadInputRegisters:
                return encodeReadInputRegisters((ReadInputRegistersRequest) modbusPdu, buffer);

            case WriteSingleCoil:
                return encodeWriteSingleCoil((WriteSingleCoilRequest) modbusPdu, buffer);

            case WriteSingleRegister:
                return encodeWriteSingleRegister((WriteSingleRegisterRequest) modbusPdu, buffer);

            case WriteMultipleCoils:
                return encodeWriteMultipleCoils((WriteMultipleCoilsRequest) modbusPdu, buffer);

            case WriteMultipleRegisters:
                return encodeWriteMultipleRegisters((WriteMultipleRegistersRequest) modbusPdu, buffer);

            case MaskWriteRegister:
                return encodeMaskWriteRegister((MaskWriteRegisterRequest) modbusPdu, buffer);

            default:
                throw new EncoderException("FunctionCode not supported: " + modbusPdu.getFunctionCode());
            }
        } finally {
            ReferenceCountUtil.release(modbusPdu);
        }
    }

    public ByteBuf encodeReadCoils(ReadCoilsRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getQuantity());

        return buffer;
    }

    public ByteBuf encodeReadDiscreteInputs(ReadDiscreteInputsRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getQuantity());

        return buffer;
    }

    public ByteBuf encodeReadHoldingRegisters(ReadHoldingRegistersRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getQuantity());

        return buffer;
    }

    public ByteBuf encodeReadInputRegisters(ReadInputRegistersRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getQuantity());

        return buffer;
    }

    public ByteBuf encodeWriteSingleCoil(WriteSingleCoilRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getValue());

        return buffer;
    }

    public ByteBuf encodeWriteSingleRegister(WriteSingleRegisterRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getValue());

        return buffer;
    }

    public ByteBuf encodeWriteMultipleCoils(WriteMultipleCoilsRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getQuantity());

        int byteCount = (request.getQuantity() + 7) / 8;
        buffer.writeByte(byteCount);

        buffer.writeBytes(request.getValues(), byteCount);

        return buffer;
    }

    public ByteBuf encodeWriteMultipleRegisters(WriteMultipleRegistersRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getQuantity());

        int byteCount = request.getQuantity() * 2;
        buffer.writeByte(byteCount);

        buffer.writeBytes(request.getValues(), byteCount);

        return buffer;
    }

    public ByteBuf encodeMaskWriteRegister(MaskWriteRegisterRequest request, ByteBuf buffer) {
        buffer.writeByte(request.getFunctionCode().getCode());
        buffer.writeShort(request.getAddress());
        buffer.writeShort(request.getAndMask());
        buffer.writeShort(request.getOrMask());

        return buffer;
    }

}