+PKG_CHECK_MODULES([librevisa], [librevisa >= 0.0.20130812],
+ [have_librevisa="yes"; CFLAGS="$CFLAGS $librevisa_CFLAGS";
+ LIBS="$LIBS $librevisa_LIBS";
+ SR_PKGLIBS="$SR_PKGLIBS librevisa"],
+ [have_librevisa="no"])
+
+# VISA SCPI backend is only compiled in if librevisa was found.
+AM_CONDITIONAL(NEED_VISA, test "x$have_librevisa" != xno)
+
+# Define HAVE_LIBREVISA in config.h if we found librevisa.
+if test "x$have_librevisa" != "xno"; then
+ AC_DEFINE_UNQUOTED(HAVE_LIBREVISA, [1],
+ [Specifies whether we have librevisa.])
+fi
+