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feat(plc4j/modbus): ModbusOptimizer fixes for discrete-input and endianness #2055

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feat(plc4j/modbus): ModbusOptimizer fixes for discrete-input and endianness #2055

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692931e
Update ModbusOptimizer.java
IsmoLeszczynski Apr 9, 2025
07bce89
Merge branch 'develop' of https://github.com/IsmoLeszczynski/plc4x in…
IsmoLeszczynski Apr 9, 2025
0909be4
Update ModbusOptimizer.java
IsmoLeszczynski Apr 16, 2025
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13 changes: 7 additions & 6 deletions ...ers/modbus/src/main/java/org/apache/plc4x/java/modbus/base/optimizer/ModbusOptimizer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -192,7 +192,7 @@ protected PlcReadResponse processReadResponses(PlcReadRequest readRequest, Map<P
}
// Go through all responses till we find one where that contains the current tag's data.
for (Response response : responses.get(tagType)) {
if(modbusTag instanceof ModbusTagCoil) {
if((modbusTag instanceof ModbusTagCoil) || (modbusTag instanceof ModbusTagDiscreteInput)) {
if(response.matchesCoil(modbusTag)) {
// If this response was invalid, return all associated addresses as equally invalid.
// TODO: Possibly it would be worth doing a single item request for each of these
Expand All @@ -204,12 +204,11 @@ protected PlcReadResponse processReadResponses(PlcReadRequest readRequest, Map<P
break;
}

// Coils are read completely different from registers.
ModbusTagCoil coilTag = (ModbusTagCoil) modbusTag;
// Coils and Discrete Inputs are read completely different from registers.

// Calculate the byte that contains the response for this Coil
byte[] responseData = response.getResponseData();
int bitPosition = coilTag.getAddress() - response.startingAddress;
int bitPosition = modbusTag.getAddress() - response.startingAddress;
int bytePosition = bitPosition / 8;
int bitPositionInByte = bitPosition % 8;
boolean isBitSet = (responseData[bytePosition] & (1 << bitPositionInByte)) != 0;
Expand All @@ -229,12 +228,14 @@ else if (response.matchesRegister(modbusTag)) {
break;
}

var byteOrder = modbusTag.getByteOrder() != null ? modbusTag.getByteOrder() : modbusContext.getByteOrder();

byte[] responseData = response.getResponseDataForTag(modbusTag);
ReadBuffer readBuffer = getReadBuffer(responseData, modbusContext.getByteOrder());
ReadBuffer readBuffer = getReadBuffer(responseData, byteOrder);
try {
PlcValue plcValue = DataItem.staticParse(readBuffer, modbusTag.getDataType(),
modbusTag.getNumberOfElements(),
modbusContext.getByteOrder() == ModbusByteOrder.BIG_ENDIAN);
byteOrder == ModbusByteOrder.BIG_ENDIAN);
values.put(tagName, new DefaultPlcResponseItem<>(PlcResponseCode.OK, plcValue));
} catch (ParseException e) {
values.put(tagName, new DefaultPlcResponseItem<>(PlcResponseCode.INTERNAL_ERROR, null));
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