A List of Common FAQs Modbus FAQsDo All the CPU’s Support Modbus Protocol?What Programming Blocks Are Needed to Use CPU as Modbus Slave?Can the CPU be a Modbus Master?Can CPU Act as a Modbus Master and Slave at the Same Time?Do All Software Blocks Have a Modbus Address?EXM FAQsHow Many SMS Messages Can be Stored in EXM CPU?How Many Phone Numbers Can be Stored in EXM CPU?Emails Are Not Being Sent by the EXM CPU. Why?Are there any limitations to expansion units on GSM PLCs?My EXM CPU Won’t Send More Than One SMS – Why?Expansion IO FAQsIs it possible to add extra IO to the CPU?Which expansion units work with which PLC CPU’s?How many expansion units can be added to a CPU?How do you change an expansion units ID?I have changed the ID of my EXM-E expansion unit but the CPU won’t communicate. What’s wrong?Once expansion unit ID’s are set, do they need to be connected in order?I have an AC expansion unit. Can I connect this to my DC powered CPU?Can Analogue Expansion Units be Added to Digital CPU?The Expansion Units LED’s are Flashing Red. What’s the Problem?Accessory FAQsDo I Need a Special Programming Lead for CPU’s?Can the CPU Log Data?What is the PRO-RS485 Cable Used For?Software FAQsDo I Need a Special Programming Lead for CPU’s?My Program Works Fine in Simulation Mode but Not in CPU. Why?My PC Software Can’t Communicate with the CPU When Using USB Cable. Why?Can I Change What’s Displayed on the CPU LCD when Powered Up?Why Won’t my Ethernet CPU communicate with the Software?