The objective of this manual is to help you troubleshoot, identify, prevent and fix common PLC and SCADA problems. The emphasis is on practical hard hitting information that goes beyond typical theory, focusing unerringly on providing you with the necessary skills to solve your problems whether it is a PLC, SCADA system, or indeed communications system linking the two together. The automation system on your plant underpins your entire operation. It is thus critical that you have the knowledge and tools to quickly identify and fix problems as they occur to ensure you have a safe, secure and productive system. No compromise is obviously possible here. This manual distils all the tips and tricks learnt over many years.