Index: trunk/Ohana/src/opihi/cmd.data/rd.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/rd.c	(revision 38062)
+++ trunk/Ohana/src/opihi/cmd.data/rd.c	(revision 38234)
@@ -170,5 +170,5 @@
   if (plane >= 0) {
     // we are requesting a specific plane (-1 : all data)
-    int tooFar = Nz ? (plane >= Nz) : (plane > Nz);
+    int tooFar = (Nz > 0) ? (plane >= Nz) : (plane > 0);
     if (tooFar) {
       gprint (GP_ERR, "-plane is too large: %d total planes\n", Nz);