fp550.rb in extface-0.5.0

- old
+ new

@@ -210,10 +210,10 @@
     def frecv(timeout) # return Frame or nil
       rframe = nil
       BAD_SEQ_MAX_COUNT.times do
         if frame_bytes = pull(timeout)
           rframe = Frame.new(frame_bytes.b)
-          if rframe.seq.ord == sequence_number(false) #accept only current sequence number as reply
+          if rframe.seq.nil? || rframe.seq.ord == sequence_number(false) #accept only current sequence number as reply
             break
           else
             errors.add :base, "Sequence mismatch"
             p "Invalid sequence (expected: #{sequence_number(false).to_s(16)}, got: #{rframe.seq.ord.to_s(16)})"
             rframe = nil #invalidate mismatch sequence frame for the last retry
\ No newline at end of file