diff --git a/slsDetectorSoftware/multiSlsDetector/multiSlsDetector.cpp b/slsDetectorSoftware/multiSlsDetector/multiSlsDetector.cpp
index 082e59afb..13ec4fad8 100644
--- a/slsDetectorSoftware/multiSlsDetector/multiSlsDetector.cpp
+++ b/slsDetectorSoftware/multiSlsDetector/multiSlsDetector.cpp
@@ -4834,16 +4834,16 @@ int multiSlsDetector::saveCalibrationFile(string fname, int imod) {
 
 
 
-int multiSlsDetector::writeRegister(int addr, int val){
+uint32_t multiSlsDetector::writeRegister(uint32_t addr, uint32_t val){
 
-	int ret, ret1=-100;
+	uint32_t ret, ret1;
 
 	for (int i=0; i<thisMultiDetector->numberOfDetectors; ++i) {
 		if (detectors[i]) {
 			ret=detectors[i]->writeRegister(addr,val);
 			if(detectors[i]->getErrorMask())
 				setErrorMask(getErrorMask()|(1<<i));
-			if (ret1==-100)
+			if (i==0)
 				ret1=ret;
 			else if (ret!=ret1) {
 				// not setting it to -1 as it is a possible value
@@ -4881,16 +4881,16 @@ int multiSlsDetector::writeAdcRegister(int addr, int val){
 }
 
 
-int multiSlsDetector::readRegister(int addr){
+uint32_t multiSlsDetector::readRegister(uint32_t addr){
 
-	int ret, ret1=-100;
+	uint32_t ret, ret1;
 
 	for (int i=0; i<thisMultiDetector->numberOfDetectors; ++i) {
 		if (detectors[i]) {
 			ret=detectors[i]->readRegister(addr);
 			if(detectors[i]->getErrorMask())
 				setErrorMask(getErrorMask()|(1<<i));
-			if (ret1==-100)
+			if (i==0)
 				ret1=ret;
 			else if (ret!=ret1) {
 				// not setting it to -1 as it is a possible value
diff --git a/slsDetectorSoftware/multiSlsDetector/multiSlsDetector.h b/slsDetectorSoftware/multiSlsDetector/multiSlsDetector.h
index c890f0330..72f8df6c4 100644
--- a/slsDetectorSoftware/multiSlsDetector/multiSlsDetector.h
+++ b/slsDetectorSoftware/multiSlsDetector/multiSlsDetector.h
@@ -1066,13 +1066,13 @@ class multiSlsDetector  : public slsDetectorUtils {
 
 
 
-  int writeRegister(int addr, int val);
+  uint32_t writeRegister(uint32_t addr, uint32_t val);
   
 
   int writeAdcRegister(int addr, int val);
   
 
-  int readRegister(int addr);
+  uint32_t readRegister(uint32_t addr);
 
   /**
       sets a bit in a register
diff --git a/slsDetectorSoftware/slsDetector/slsDetector.cpp b/slsDetectorSoftware/slsDetector/slsDetector.cpp
index 617c2d06e..16ae3835e 100644
--- a/slsDetectorSoftware/slsDetector/slsDetector.cpp
+++ b/slsDetectorSoftware/slsDetector/slsDetector.cpp
@@ -2309,13 +2309,13 @@ int slsDetector::digitalTest( digitalTestMode mode, int imod){
 
 /* write or read register */
 
-int slsDetector::writeRegister(int addr, int val){
+uint32_t slsDetector::writeRegister(uint32_t addr, uint32_t val){
 
-	int retval=-1;
+	uint32_t retval = 0;
 	int fnum=F_WRITE_REGISTER;
 	int ret=FAIL;
 	char mess[MAX_STR_LENGTH]="";
-	int arg[2];
+	uint32_t arg[2];
 	arg[0]=addr;
 	arg[1]=val;
 
@@ -2358,7 +2358,7 @@ int slsDetector::writeAdcRegister(int addr, int val){
 	int ret=FAIL;
 	char mess[MAX_STR_LENGTH]="";
 
-	int arg[2];
+	uint32_t arg[2];
 	arg[0]=addr;
 	arg[1]=val;
 
@@ -2397,13 +2397,13 @@ int slsDetector::writeAdcRegister(int addr, int val){
 
 
 
-int slsDetector::readRegister(int addr){
+uint32_t slsDetector::readRegister(uint32_t addr){
 
-	int retval=-1;
+	uint32_t retval = 0;
 	int fnum=F_READ_REGISTER;
 	int ret=FAIL;
 	char mess[MAX_STR_LENGTH]="";
-	int arg;
+	uint32_t arg;
 	arg=addr;
 
 
diff --git a/slsDetectorSoftware/slsDetector/slsDetector.h b/slsDetectorSoftware/slsDetector/slsDetector.h
index d1581eeab..bbd1078b9 100644
--- a/slsDetectorSoftware/slsDetector/slsDetector.h
+++ b/slsDetectorSoftware/slsDetector/slsDetector.h
@@ -864,7 +864,7 @@ class slsDetector : public slsDetectorUtils, public energyConversion {
       \returns current register value
 
   */
-  int writeRegister(int addr, int val);
+  uint32_t writeRegister(uint32_t addr, uint32_t val);
   
 
   /** 
@@ -882,7 +882,7 @@ class slsDetector : public slsDetectorUtils, public energyConversion {
       \returns current register value
 
   */
-  int readRegister(int addr);
+  uint32_t readRegister(uint32_t addr);
 
   /**
       sets a bit in a register
diff --git a/slsDetectorSoftware/slsDetector/slsDetectorUtils.h b/slsDetectorSoftware/slsDetector/slsDetectorUtils.h
index 4e44529ed..e905ce261 100644
--- a/slsDetectorSoftware/slsDetector/slsDetectorUtils.h
+++ b/slsDetectorSoftware/slsDetector/slsDetectorUtils.h
@@ -497,7 +497,7 @@ class slsDetectorUtils :  public slsDetectorActions, public postProcessing {
       
       DO NOT USE!!! ONLY EXPERT USER!!!
   */
-  virtual int writeRegister(int addr, int val)=0; 
+  virtual uint32_t writeRegister(uint32_t addr, uint32_t val)=0;
 
 
   /** 
@@ -508,7 +508,7 @@ class slsDetectorUtils :  public slsDetectorActions, public postProcessing {
       
       DO NOT USE!!! ONLY EXPERT USER!!!
   */
-  virtual int writeAdcRegister(int addr, int val)=0; 
+  virtual int writeAdcRegister(int addr, int val)=0;
 
  
   /** 
@@ -518,7 +518,7 @@ class slsDetectorUtils :  public slsDetectorActions, public postProcessing {
 
       DO NOT USE!!! ONLY EXPERT USER!!!
   */
-  virtual int readRegister(int addr)=0;
+  virtual uint32_t readRegister(uint32_t addr)=0;
 
 
   /**