diff --git a/doc/version-history.rst b/doc/version-history.rst
index 2873afbe..be42f031 100644
--- a/doc/version-history.rst
+++ b/doc/version-history.rst
@@ -8,6 +8,7 @@ v1.11.0
   to FPGA class.
 * Improved documentation.
 * Public constants to explain meaning of the numbers
+* mpuCommands redesign
 
 v1.10.1
 -------
diff --git a/include/cRIO/FPGA.h b/include/cRIO/FPGA.h
index 628011d3..6d5b6191 100644
--- a/include/cRIO/FPGA.h
+++ b/include/cRIO/FPGA.h
@@ -37,6 +37,20 @@ namespace cRIO {
 
 class MPU;
 
+/**
+ * Commands for FPGA MPU unit.
+ */
+enum MPUCommands {
+    WRITE = 1,
+    READ_US = 2,
+    READ_MS = 3,
+    WAIT_US = 100,
+    WAIT_MS = 101,
+    IRQ = 240,
+    TELEMETRY = 254,
+    RESET = 255,
+};
+
 /**
  * Interface class for cRIO FPGA. Subclasses can talk either to the real HW, or
  * be a software simulator.
diff --git a/src/LSST/cRIO/FPGA.cpp b/src/LSST/cRIO/FPGA.cpp
index 2722430b..63f993b1 100644
--- a/src/LSST/cRIO/FPGA.cpp
+++ b/src/LSST/cRIO/FPGA.cpp
@@ -155,6 +155,8 @@ void FPGA::mpuCommands(MPU &mpu, const std::chrono::duration<double> &timeout) {
         std::vector<uint8_t> data;
 
         data.push_back(mpu.getBus());
+        data.push_back(cmd.buffer.size() + 2);
+        data.push_back(MPUCommands::WRITE);
         data.push_back(cmd.buffer.size());
         data.insert(data.end(), cmd.buffer.begin(), cmd.buffer.end());