Hi, My name is Faiz & I am from Malaysia. Have some problem with my old SMC Gateway EX500-Gen 1. I have been searching for the meaning of MS & NS on the device but still find it out. Apart from that, another problem that I have is the power indicator (PWR) which it did not lit up even though there is 24vdc supply going in. Most of the time when I shutdown the system, something will happen. Few questions that I guess I really need help : 1. What could cause the PWR indicator light not ON? 2. Why sometimes the device able to ON & suddenly later after that no PWR indicator & also all COM indicator OFF? 3. What could be the root cause that could cause this problem? Thanks.