problem)
The IEC 61131 standard sates the five IEC 61131-3 languages. Each of the five languages offers distinct advantages so, depending upon application, and is often advantageous to combine them. Using internet, describe the distinct advantages for other four languages except IL briefly.

Instruction List (IL)
• Text-based language similar to processor “assembly” code
• Executes the fastest of the five languages;
• Easily imported/exported

problem)
State TWO advantages for using the following bus standards in an industrial process:
a) Modbus-TCP
b) Modbus-RTU
c) Device Net
d) Profibus

problem)
State commonly found components of the Supervisory control and data acquisition (SCADA) system.

problem)
Decribe the function of the HMI in a SCADA system.

problem)
Modbus RTU is one of the field bus standards used in industry.
a) describe with the aid of sketch the structure of the transmitted and received master/slave protocol frame.

problem )
State one advantage of using CAN-open over Modbus RTU for a field bus.

problem) Modbus RTU can be used with either RS232 or RS485, describe why RS485 is preferred method of communication between a master and slaves.

problem) Using the internet, locate information on a safety PLC.
Briefly describe the difference in concept between a standard PLC and a safety PLC.