the agency i work for is in the process of upgrading roughly 50 of these schneider PLCs from the older tsx. Also integrating wonderware/Unity, trio radios- all shneider products. As a field tech im not involved in the installation of these, this has been contracted. At several of the various stations that have been put online we will see via SCADA a communication failure and it will not return. Upon inspection at the site the normally colorful flashing displays across the rack will be dark no status lights illuminated at all. first thought is this power supply is not receiving any power BUT testing with a meter shows 120v at the terminals on the power supply. only when breaker is cycled sometimes a couple times the rack comes back up. we have no idea what could be the cause. have tried simulating power fails, sags swells etc. these also have pure sine ups with avr and its happened with and without those connected. Anybody heard of this??
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