diff --git a/src/Constants.hpp b/src/Constants.hpp
index b0e0186..09bd2e6 100644
--- a/src/Constants.hpp
+++ b/src/Constants.hpp
@@ -36,4 +36,4 @@ const char* error5 PROGMEM = "error5";
 const char* errorMessages[6];
 */
 
-#define MAX_DP_LENGTH 4
+#define MAX_DP_LENGTH 8
diff --git a/src/OptolinkKW.cpp b/src/OptolinkKW.cpp
index 2dd59fc..88fcfae 100644
--- a/src/OptolinkKW.cpp
+++ b/src/OptolinkKW.cpp
@@ -129,7 +129,7 @@ void OptolinkKW::_syncHandler() {
 
 //
 void OptolinkKW::_sendHandler() {
-  uint8_t buff[6];
+  uint8_t buff[MAX_DP_LENGTH+4];
   if (_writeMessageType) {
     // type is WRITE
     // has length of 4 chars + length of value
@@ -211,7 +218,7 @@ bool OptolinkKW::_transmit(uint16_t address, uint8_t length, bool write, uint8_t
     memcpy(_value, value, _length);
   }
   _rcvBufferLen = 0;
-  memset(_rcvBuffer, 0, 4);
+  memset(_rcvBuffer, 0, _length);
   _setAction(PROCESS);
   return true;
 }
diff --git a/src/OptolinkKW.hpp b/src/OptolinkKW.hpp
index c5519d8..0f50202 100644
--- a/src/OptolinkKW.hpp
+++ b/src/OptolinkKW.hpp
@@ -52,8 +52,8 @@ class OptolinkKW {
   uint16_t _address;
   uint8_t _length;
   bool _writeMessageType;
-  uint8_t _value[4];
-  uint8_t _rcvBuffer[4];
+  uint8_t _value[MAX_DP_LENGTH];
+  uint8_t _rcvBuffer[MAX_DP_LENGTH];
   uint8_t _rcvBufferLen;
   uint8_t _rcvLen;
   uint32_t _lastMillis;