I work for a company that manufactures HVAC equipment. I have an inside application for a filling station that will require the use of a PLC. It will most likely have 13 digital inputs and 7 digital outputs. Please help me select a PLC for this application. I will have to buy the software and cables as well. We currently use the Johnson DX-9100 and 9200 series DDC. The Johnson controller is not suitable for this application. Thanks.