diff --git a/slsDetectorServers/ctbDetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/ctbDetectorServer/slsDetectorFunctionList.c
index 97357cf12..cfd71ef7e 100644
--- a/slsDetectorServers/ctbDetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/ctbDetectorServer/slsDetectorFunctionList.c
@@ -1145,9 +1145,11 @@ int getNumTransceiverSamples() { return ntSamples; }
 int setExpTime(int64_t val) {
     setPatternWaitInterval(0, val);
 
-    // validate for tolerance
+    // Tolerance: three clock periods in ns.
     int64_t retval = getExpTime();
-    if (val != retval) {
+    int64_t toleranceNs = 3 * (1000000000 / clkFrequency[RUN_CLK]);
+    int64_t diff = val - retval;
+    if (diff < -toleranceNs || diff > toleranceNs) {
         return FAIL;
     }
     return OK;
diff --git a/slsDetectorServers/slsDetectorServer/src/loadPattern.c b/slsDetectorServers/slsDetectorServer/src/loadPattern.c
index 929460897..021295476 100644
--- a/slsDetectorServers/slsDetectorServer/src/loadPattern.c
+++ b/slsDetectorServers/slsDetectorServer/src/loadPattern.c
@@ -307,7 +307,9 @@ uint64_t getPatternWaitInterval(int level) {
         LOG(logERROR, ("runclk is 0. Cannot divide by 0. Returning -1.\n"));
         return -1;
     }
-    return numClocks / (NS_TO_CLK_CYCLE * runclk);
+    double conv = NS_TO_CLK_CYCLE * runclk;
+    uint64_t waitNs = (uint64_t)(numClocks / conv + 0.5);
+    return waitNs;
 }
 
 int validate_setPatternWaitClocksAndInterval(char *message, int level,
diff --git a/slsDetectorServers/slsDetectorServer/src/slsDetectorServer_funcs.c b/slsDetectorServers/slsDetectorServer/src/slsDetectorServer_funcs.c
index 19bee554a..49ab27d3e 100644
--- a/slsDetectorServers/slsDetectorServer/src/slsDetectorServer_funcs.c
+++ b/slsDetectorServers/slsDetectorServer/src/slsDetectorServer_funcs.c
@@ -5867,7 +5867,7 @@ int set_clock_frequency(int file_des) {
             if (getFrequency(c) == val) {
                 LOG(logINFO, ("Same %s: %d %s\n", modeName, val, "Hz"));
             } else {
-                int ret = setFrequency(c, val); // MM: Poblem
+                int ret = setFrequency(c, val);
                 if (ret == FAIL) {
                     sprintf(mess, "Could not set %s to %d %s\n", modeName, val,"Hz");
                     LOG(logERROR, (mess));
diff --git a/slsDetectorServers/xilinx_ctbDetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/xilinx_ctbDetectorServer/slsDetectorFunctionList.c
index 1c1a55a8a..962b9d3fa 100644
--- a/slsDetectorServers/xilinx_ctbDetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/xilinx_ctbDetectorServer/slsDetectorFunctionList.c
@@ -1055,9 +1055,11 @@ int getNumTransceiverSamples() {
 int setExpTime(int64_t val) {
     setPatternWaitInterval(0, val);
 
-    // validate for tolerance
+    // Tolerance: three clock periods in ns.
     int64_t retval = getExpTime();
-    if (val != retval) {
+    int64_t toleranceNs = 3 * (1000000000 / clkFrequency[RUN_CLK]);
+    int64_t diff = val - retval;
+    if (diff < -toleranceNs || diff > toleranceNs) {
         return FAIL;
     }
     return OK;