diff --git a/src/lib/ebus/data.cpp b/src/lib/ebus/data.cpp
index b444990d..eef428fb 100644
--- a/src/lib/ebus/data.cpp
+++ b/src/lib/ebus/data.cpp
@@ -367,7 +367,7 @@ result_t SingleDataField::create(const char* typeNameStr, const unsigned char le
 	const PartType partType, int divisor, map<unsigned int, string> values,
 	SingleDataField* &returnField)
 {
-	for (size_t i = 0; i < sizeof(dataTypes) / sizeof(dataType_t); i++) { // TODO use a map
+	for (size_t i = 0; i < sizeof(dataTypes) / sizeof(dataType_t); i++) {
 		const dataType_t* dataType = &dataTypes[i];
 		if (strcasecmp(typeNameStr, dataType->name) != 0)
 			continue;
@@ -748,8 +748,8 @@ result_t StringDataField::writeSymbols(istringstream& input,
 		return RESULT_OK;
 	}
 	result_t result;
-	size_t i = 0;
-	for (size_t offset = start; i < count; offset += incr, i++) {
+	size_t i = 0, offset;
+	for (offset = start; i < count; offset += incr, i++) {
 		switch (m_dataType.type)
 		{
 		case bt_hexstr:
@@ -856,10 +856,9 @@ result_t StringDataField::writeSymbols(istringstream& input,
 			}
 			break;
 		}
-		if (remainder && input.eof() && i > 0) {
-			count = (offset-start)*incr;
+		if (remainder && input.eof() && i > 0)
 			break;
-		}
+
 		lastLast = last;
 		last = value;
 		if ((m_dataType.flags & BCD) != 0 && ((m_dataType.flags & REQ) != 0 || value != m_dataType.replacement)) {
@@ -872,10 +871,10 @@ result_t StringDataField::writeSymbols(istringstream& input,
 		output[baseOffset + offset] = (unsigned char)value;
 	}
 
-	if (!remainder && i < m_length) // TODO check with bt_tim and m_length == 1
+	if (!remainder && i < count)
 		return RESULT_ERR_EOF; // input too short
 	if (length!=NULL)
-		*length = (unsigned char)count;
+		*length = (unsigned char)((offset-start)*incr);
 	return RESULT_OK;
 }
 
diff --git a/src/lib/ebus/message.cpp b/src/lib/ebus/message.cpp
index da27496e..82e9d0ea 100644
--- a/src/lib/ebus/message.cpp
+++ b/src/lib/ebus/message.cpp
@@ -733,7 +733,8 @@ ChainedMessage::ChainedMessage(const string circuit, const string name,
 		: Message(circuit, name, isWrite, false, comment,
 		  srcAddress, dstAddress, id,
 		  data, deleteData, pollPriority, condition),
-		  m_ids(ids), m_lengths(lengths)
+		  m_ids(ids), m_lengths(lengths),
+		  m_maxTimeDiff(m_ids.size()*15) // 15 seconds per message
 {
 	size_t cnt = ids.size();
 	m_lastMasterDatas = (SymbolString**)calloc(cnt, sizeof(SymbolString*));
@@ -807,7 +808,7 @@ result_t ChainedMessage::prepareMasterPart(SymbolString& master, istringstream&
 		return RESULT_ERR_NOTFOUND;
 
 	SymbolString allData(false);
-	result_t result = m_data->write(input, pt_masterData, allData, 0, separator); // TODO cache this?
+	result_t result = m_data->write(input, pt_masterData, allData, 0, separator);
 	if (result != RESULT_OK)
 		return result;
 	size_t pos = 0, addData = 0;
@@ -896,7 +897,7 @@ result_t ChainedMessage::storeLastData(const PartType partType, SymbolString& da
 		if (m_lastSlaveUpdateTimes[index]>maxTime) {
 			maxTime = m_lastSlaveUpdateTimes[index];
 		}
-		if (minTime==0 || maxTime==0 || maxTime-minTime>30) {// TODO constant multiplied by number of messages
+		if (minTime==0 || maxTime==0 || maxTime-minTime>m_maxTimeDiff) {
 			return RESULT_CONTINUE;
 		}
 	}
@@ -904,7 +905,6 @@ result_t ChainedMessage::storeLastData(const PartType partType, SymbolString& da
 	SymbolString master(false);
 	SymbolString slave(false);
 	size_t offset = 5+(m_ids[0].size()-2); // skip QQ, ZZ, PB, SB, NN
-	//getIdLength(); // TODO usually shorter than real ID, only use for external interface
 	for (index=0; index<m_ids.size(); index++) {
 		SymbolString* add = m_lastMasterDatas[index];
 		size_t end = 5+(*add)[4];
diff --git a/src/lib/ebus/message.h b/src/lib/ebus/message.h
index fb9d2a26..f27fb6b8 100644
--- a/src/lib/ebus/message.h
+++ b/src/lib/ebus/message.h
@@ -589,10 +589,13 @@ protected:
 private:
 
 	/** the primary, secondary, and optional further ID bytes for each part of the chain. */
-	vector< vector<unsigned char> > m_ids;
+	const vector< vector<unsigned char> > m_ids;
 
 	/** the data length for each part of the chain. */
-	vector<unsigned char> m_lengths;
+	const vector<unsigned char> m_lengths;
+
+	/** the maximum allowed time difference of any data pair. */
+	const time_t m_maxTimeDiff;
 
 	/** array of the last seen master datas. */
 	SymbolString** m_lastMasterDatas;