diff --git a/slsDetectorServers/xilinx_ctbDetectorServer/RegisterDefs.h b/slsDetectorServers/xilinx_ctbDetectorServer/RegisterDefs.h
index 1ff521b05..438355c46 100644
--- a/slsDetectorServers/xilinx_ctbDetectorServer/RegisterDefs.h
+++ b/slsDetectorServers/xilinx_ctbDetectorServer/RegisterDefs.h
@@ -131,7 +131,7 @@
 
 /* REG no_Samples_X_Reg */
 #define NO_SAMPLES_X_REG 0xa00cUL
-#define NO_SAMPLES_X_MSK 0x1fffUL
+#define NO_SAMPLES_X_MSK 0x7FFFFFFFUL
 #define NO_SAMPLES_X_OFST 0
 
 /* REG count_Frames_From_Reg_1 */
diff --git a/slsDetectorServers/xilinx_ctbDetectorServer/bin/xilinx_ctbDetectorServer_developer b/slsDetectorServers/xilinx_ctbDetectorServer/bin/xilinx_ctbDetectorServer_developer
index 2b82c81db..4aec0c165 100755
Binary files a/slsDetectorServers/xilinx_ctbDetectorServer/bin/xilinx_ctbDetectorServer_developer and b/slsDetectorServers/xilinx_ctbDetectorServer/bin/xilinx_ctbDetectorServer_developer differ
diff --git a/slsDetectorServers/xilinx_ctbDetectorServer/slsDetectorServer_defs.h b/slsDetectorServers/xilinx_ctbDetectorServer/slsDetectorServer_defs.h
index 71d415745..0ac8e1d5d 100644
--- a/slsDetectorServers/xilinx_ctbDetectorServer/slsDetectorServer_defs.h
+++ b/slsDetectorServers/xilinx_ctbDetectorServer/slsDetectorServer_defs.h
@@ -60,7 +60,7 @@
 #define DEFAULT_DELAY                 (0)
 
 #define MAX_TRANSCEIVER_MASK    (0xF)
-#define MAX_TRANSCEIVER_SAMPLES (0x1FFF)
+#define MAX_TRANSCEIVER_SAMPLES (0x7FFFFFFF)
 
 #define MAX_ANALOG_SAMPLES  (0x3FFF)
 #define MAX_DIGITAL_SAMPLES (0x3FFF)
diff --git a/slsDetectorSoftware/tests/Caller/test-Caller-chiptestboard.cpp b/slsDetectorSoftware/tests/Caller/test-Caller-chiptestboard.cpp
index 54231950c..e557363aa 100644
--- a/slsDetectorSoftware/tests/Caller/test-Caller-chiptestboard.cpp
+++ b/slsDetectorSoftware/tests/Caller/test-Caller-chiptestboard.cpp
@@ -932,6 +932,11 @@ TEST_CASE("tsamples", "[.cmdcall]") {
             caller.call("tsamples", {}, -1, GET, oss);
             REQUIRE(oss.str() == "tsamples 450\n");
         }
+        if (det_type == defs::XILINX_CHIPTESTBOARD) {
+            std::ostringstream oss;
+            caller.call("tsamples", {"2147483647"}, -1, PUT, oss);
+            REQUIRE(oss.str() == "tsamples 2147483647\n");
+        }
         for (int i = 0; i != det.size(); ++i) {
             det.setNumberOfTransceiverSamples(prev_val[i], {i});
         }
diff --git a/slsSupportLib/include/sls/versionAPI.h b/slsSupportLib/include/sls/versionAPI.h
index 2911477d9..cf4b1ba25 100644
--- a/slsSupportLib/include/sls/versionAPI.h
+++ b/slsSupportLib/include/sls/versionAPI.h
@@ -7,6 +7,6 @@
 #define APIGOTTHARD2 "0.0.0 0x250909"
 #define APIMOENCH    "0.0.0 0x250909"
 #define APIEIGER     "0.0.0 0x250909"
-#define APIXILINXCTB "0.0.0 0x260106"
+#define APIXILINXCTB "0.0.0 0x260121"
 #define APIJUNGFRAU  "0.0.0 0x250909"
 #define APIMYTHEN3   "0.0.0 0x250922"