I am BE instru graduate, currently working as a service eng. which course will allow me to switch to core instrumentation sector (plcs etc)?

I have been working as a service engg in analytical instruments for 2 years now but I wish to switch to core sector in instrumentation like PLC, automation etc. Is it advisable to do so?, if yes.which course would help me best to switch at this point? is der any other course to improve my prospects