diff --git a/dsmApp/src/MD90Driver.cpp b/dsmApp/src/MD90Driver.cpp
index db5907a..33d0181 100644
--- a/dsmApp/src/MD90Driver.cpp
+++ b/dsmApp/src/MD90Driver.cpp
@@ -185,7 +185,7 @@ asynStatus MD90Axis::sendAccelAndVelocity(double acceleration, double velocity)
   // Velocity provided in steps/sec
   // Our unit step size of the encoder is 10 nm, but the motor moves in steps approx. 5 micrometers.
   // Motor controller accepts step frequency in Hz.
-  freq = NINT(fabs(velocity / 500.));
+  freq = NINT(fabs(velocity / COUNTS_PER_STEP));
   sprintf(pC_->outString_, "SSF %d", freq);
   status = pC_->writeReadController();
   if (!status) {
@@ -446,7 +446,7 @@ asynStatus MD90Axis::poll(bool *moving)
   if (comStatus) goto skip;
   // The response string is of the form "0: Current step frequency: 100"
   sscanf(pC_->inString_, "%d: %[^:]: %d", &replyStatus, replyString, &replyValue);
-  velocity = replyValue * 500.0;
+  velocity = replyValue * COUNTS_PER_STEP;
   setDoubleParam(pC_->motorVelocity_, velocity);
 
   // Read the current motor integral gain (range 1-1000)
diff --git a/dsmApp/src/MD90Driver.h b/dsmApp/src/MD90Driver.h
index 0b1e056..80e1859 100644
--- a/dsmApp/src/MD90Driver.h
+++ b/dsmApp/src/MD90Driver.h
@@ -2,9 +2,6 @@
 FILENAME...   MD90Driver.h
 USAGE...      Motor driver support for the DSM MD-90 controller.
 
-Mark Rivers
-March 1, 2012
-
 */
 
 #include "asynMotorController.h"
@@ -15,6 +12,8 @@ March 1, 2012
 // No controller-specific parameters yet
 #define NUM_MD90_PARAMS 0  
 
+#define COUNTS_PER_STEP    1000.0
+
 class epicsShareClass MD90Axis : public asynMotorAxis
 {
 public: