Recently, i have encountered this problem regarding IM151-7 module, first is the personel in-charge reported it busted (burnt) in which the reason is still not clarified (currently under investigation), though im still a bit puzzled because there are output in the modules attached. though i couldn't communicate with the module itself (which i think is the busted part), to confirm, ive tried to connect to another IM 151-7 module and yes, i connected..
the second problem arises, though i connected with it, the module indicates a [?] and tells that it needs a master module. so i really couldn't see whats inside of it. the personel said that there is no master module existed and only relies on the memory card inserted, so im assuming that the original programmer didn't want others to connect to it though.
how would i be able to check on the other i/o modules if they are also damaged if i ont have a master module?