  Recently we studied communication delay in distributed control of untimed
discrete-event systems based on supervisor localization. We proposed a property
called delay-robustness: the overall system behavior controlled by distributed
controllers with communication delay is logically equivalent to its delay-free
counterpart. In this paper we extend our previous work to timed discrete-event
systems, in which communication delays are counted by a special clock event
{\it tick}. First, we propose a timed channel model and define timed
delay-robustness; for the latter, a polynomial verification procedure is
presented. Next, if the delay-robust property does not hold, we introduce
bounded delay-robustness, and present an algorithm to compute the maximal delay
bound (measured by number of ticks) for transmitting a channeled event.
Finally, we demonstrate delay-robustness on the example of an under-load
tap-changing transformer.
