diff --git a/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.c
index 9b53f906f..8d80d5438 100644
--- a/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.c
@@ -1861,9 +1861,9 @@ int getPrimaryInterface() {
     return ((bus_r(CONFIG_REG) & CONFIG_INNR_PRIMRY_INTRFCE_MSK) ? 1 : 0);
 }
 
-void setupHeader(int iRxEntry, enum interfaceType type, uint32_t destip,
-                 uint64_t destmac, uint16_t destport, uint64_t sourcemac,
-                 uint32_t sourceip, uint16_t sourceport) {
+int setupHeader(int iRxEntry, enum interfaceType type, uint32_t destip,
+                uint64_t destmac, uint16_t destport, uint64_t sourcemac,
+                uint32_t sourceip, uint16_t sourceport) {
 
     // start addr
     uint32_t addr = (type == INNER ? RXR_ENDPOINT_INNER_START_REG
@@ -1904,16 +1904,15 @@ void setupHeader(int iRxEntry, enum interfaceType type, uint32_t destip,
 
     calcChecksum(udp);
 
-    // force FPGA writes to be aligned and in order
-    uint32_t words[sizeof(udp_header) / sizeof(uint32_t)];
-    memcpy(words, udp, sizeof(udp_header));
-    for (size_t i = 0; i != sizeof(words) / sizeof(words[0]); ++i) {
-        bus_w(addr + i * 2, words[i]);
+    if (bus_w_block(addr, udp, sizeof(udp_header)) == FAIL) {
+        LOG(logERROR, ("Failed to write UDP header\n"));
+        return FAIL;
     }
 
     if (iRxEntry < numUdpDestinations) {
         LOG(logINFO, ("\tIP checksum : 0x%lx\n\n", udp->ip_checksum));
     }
+    return OK;
 }
 
 void calcChecksum(udp_header *udp) {
@@ -2030,21 +2029,33 @@ int configureMAC() {
 #endif
         if (numInterfaces == 2) {
             // bottom
-            setupHeader(iRxEntry, OUTER, dstip, dstmac, dstport, srcmac, srcip,
-                        srcport);
+            if (setupHeader(iRxEntry, OUTER, dstip, dstmac, dstport, srcmac,
+                            srcip, srcport) == FAIL) {
+                LOG(logERROR, ("Failed to setup outer header\n"));
+                return FAIL;
+            }
             // top
-            setupHeader(iRxEntry, INNER, dstip2, dstmac2, dstport2, srcmac2,
-                        srcip2, srcport2);
+            if (setupHeader(iRxEntry, INNER, dstip2, dstmac2, dstport2, srcmac2,
+                            srcip2, srcport2) == FAIL) {
+                LOG(logERROR, ("Failed to setup inner header\n"));
+                return FAIL;
+            }
         }
         // single interface
         else {
             // default
             if (selInterface == 0) {
-                setupHeader(iRxEntry, OUTER, dstip, dstmac, dstport, srcmac,
-                            srcip, srcport);
+                if (setupHeader(iRxEntry, OUTER, dstip, dstmac, dstport, srcmac,
+                                srcip, srcport) == FAIL) {
+                    LOG(logERROR, ("Failed to setup outer header\n"));
+                    return FAIL;
+                }
             } else {
-                setupHeader(iRxEntry, INNER, dstip, dstmac, dstport, srcmac,
-                            srcip, srcport2);
+                if (setupHeader(iRxEntry, INNER, dstip, dstmac, dstport, srcmac,
+                                srcip, srcport2) == FAIL) {
+                    LOG(logERROR, ("Failed to setup inner header\n"));
+                    return FAIL;
+                }
             }
         }
     }
diff --git a/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.h b/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.h
index e65ed3d37..5170dfeca 100644
--- a/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.h
+++ b/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.h
@@ -167,9 +167,9 @@ int getFirstUDPDestination();
 void setFirstUDPDestination(int value);
 void selectPrimaryInterface(int val);
 int getPrimaryInterface();
-void setupHeader(int iRxEntry, enum interfaceType type, uint32_t destip,
-                 uint64_t destmac, uint16_t destport, uint64_t sourcemac,
-                 uint32_t sourceip, uint16_t sourceport);
+int setupHeader(int iRxEntry, enum interfaceType type, uint32_t destip,
+                uint64_t destmac, uint16_t destport, uint64_t sourcemac,
+                uint32_t sourceip, uint16_t sourceport);
 void calcChecksum(udp_header *udp);
 
 int configureMAC();
diff --git a/slsDetectorServers/slsDetectorServer/include/blackfin.h b/slsDetectorServers/slsDetectorServer/include/blackfin.h
index d6a14f134..698a19e16 100644
--- a/slsDetectorServers/slsDetectorServer/include/blackfin.h
+++ b/slsDetectorServers/slsDetectorServer/include/blackfin.h
@@ -50,6 +50,13 @@ void bus_w(u_int32_t offset, u_int32_t data);
  */
 u_int32_t bus_r(u_int32_t offset);
 
+/**
+ * Force FPGA writes to be aligned and in order
+ * by writing 32 bit words to the bus
+ * @returns FAIL if size is not a non-zero multiple of sizeof(uint32_t), else OK
+ */
+int bus_w_block(u_int32_t offset, const void *src, size_t size);
+
 /**
  * Read from a 64 bit register
  * @param aLSB LSB offset address
diff --git a/slsDetectorServers/slsDetectorServer/src/blackfin.c b/slsDetectorServers/slsDetectorServer/src/blackfin.c
index 868708ab0..64ee3ff23 100644
--- a/slsDetectorServers/slsDetectorServer/src/blackfin.c
+++ b/slsDetectorServers/slsDetectorServer/src/blackfin.c
@@ -9,6 +9,7 @@
 
 #include <fcntl.h>    // open
 #include <stdio.h>    // fopen
+#include <string.h>   //memcpy
 #include <sys/mman.h> // mmap
 #include <unistd.h>   // usleep
 
@@ -46,6 +47,22 @@ u_int32_t bus_r(u_int32_t offset) {
     return *ptr1;
 }
 
+int bus_w_block(u_int32_t offset, const void *src, size_t size) {
+    uint32_t step = 1 << MEM_MAP_SHIFT;
+    if (size == 0 || size % sizeof(uint32_t) != 0) {
+        LOG(logERROR, ("Could not write block: size %zu is not a non-zero "
+                       "multiple of %zu\n",
+                       size, sizeof(uint32_t)));
+        return FAIL;
+    }
+    uint32_t words[size / sizeof(uint32_t)];
+    memcpy(words, src, size);
+    for (size_t i = 0; i != sizeof(words) / sizeof(words[0]); ++i) {
+        bus_w(offset + i * step, words[i]);
+    }
+    return OK;
+}
+
 int64_t get64BitReg(int aLSB, int aMSB) {
     int64_t v64;
     u_int32_t vLSB, vMSB;
diff --git a/slsDetectorServers/slsDetectorServer/src/common.c b/slsDetectorServers/slsDetectorServer/src/common.c
index cd7adab63..7d0abef79 100644
--- a/slsDetectorServers/slsDetectorServer/src/common.c
+++ b/slsDetectorServers/slsDetectorServer/src/common.c
@@ -817,4 +817,4 @@ int deleteItem(char *mess, int isFile, const char *absPath, char *errorPrefix) {
                   absPath, errorPrefix));
 
     return OK;
-}
\ No newline at end of file
+}