PLC test 1 Actual Questions With 100% Guaranteed Verified Answers.

4 main comp. of programmable logic controller - correct answer processor, power supply, I/O, programming device define interface - correct answer two systems interacting with one another Define real world - correct answer physical devices that need to be hardwired Define discrete - correct answer I/Os that are ON/OFF; Open/closed What is DC - correct answer direct current what is CPU - correct answer central processing unit what is plc - correct answer programmable logic controller what is adc - correct answer analog to digital controller what is dac - correct answer digital to analog controller what is nema - correct answer national electrical manufacturers association what is ac - correct answer alternating current what is I/O - correct answer inputs and outputs two reasons to apply optical isolation - correct answer 1. eliminates possibility of damaging the processor due to in line voltage 2. protects processor from noise, voltage transients, voltage spikes Are Triacs are susceptible to "dielectric-type" breakdown if the maximum peak voltage level is exceeded. - correct answer Yes Briefly describe why a hardwired emergency-stop circuit is recommended for PLC installations. - correct answer So program logic can take approximate action for a safe restart of the system Briefly describe the function of an interposing relay. - correct answer When it is necessary to control large loads larger than the rating of an individual output circuit, a control relay is connected to output module. Name two things that are not normally sources of electrical noise? - correct answer indicator lamp, overload heaters T or F. To ensure maximum benefit of shielding, the shield of a shielded cable must be terminated and grounded at both ends. - correct answer False what is e stop - correct answer emergency stop Can Electromagnetic interference (EMI) can be reduced with the proper grounding of equipment - correct answer yes List three environmental considerations when installing PLC equipment. - correct answer . Temperature, dust, vibration, and humidit T or F The processor is often referred to as the BRAIN of the programmable controller - correct answer true Briefly describe volatile memory. - correct answer loses memory when power is lost The most common type of volatile memory is - correct answer RAM What is meant by the term Reverse Video? - correct answer 0Objects (symbols, etc .) are shown with a reverse background co what is a watchdog timer - correct answer an outside timer that times the program automatically. If it takes longer then the set time, it will stop and the program will turn off. What special precautions should be taken with lithium batteries? - correct answer water Describe the four steps of a typical PLC processor scan. - correct answer 1: Determine the status of input devices (on or off), 2: Read and solve the logic of the program (ladder logic), 3: Update the output devices (turn on or off), 4: Evaluate communications and housekeeping procedures Define the term byte. - correct answer group of 8 bits In a PLC-5, data file 5 is what type of file? - correct answer counter control file c5 Define the term scope tags. - correct answer I/O tags describe REAL - correct answer s a memory location for a 32 bit value that contains a mantissa; describe bool - correct answer memory location for a single bit describe SINT - correct answer memory location for storing a short integer 8 bit What is an array? - correct answer is a contiguous block of memory of the same data type and can be one, two, or 3 dimensional Describe the difference between a wiring diagram and a ladder (schematic) diagram - correct answer wiring - shows physical locations and physical connections ladder - electrical relationships w/o physical locations; usually only shows the control cct Contacts wired in parallel have what relationship? - correct answer OR Contacts wired in series have what relationship? - correct answer AND The two main vertical lines of a ladder diagram are often referred to as: - correct answer rails The horizontal lines of a ladder diagram are referred to as: - correct answer rungs When an N.O. limit switch is wired to an input module, and programmed using an N.O. contact symbol (EXAMINE ON), the instruction will be true when.. - correct answer when the limit switch is closed The XIO instruction is the same as: - correct answer Examine On The XIC instruction is the same as: - correct answer Examine off What does the term On-Line Programming mean? - correct answer changes are being made while the program has been downloaded and is running What is the FORCE feature used for? - correct answer The force feature is used to force an examine either off or on, regardless of their actual status. Describe briefly the shorthand method of programming using the RSLogix software. - correct answer The shorthand method will require that the electrician or technician know the mnemonic names for each program instruction .By using the mnemonic names, rather than clicking on the symbol buttons at the top of the programming area, programs can be entered more quickly. The mnemonic names are typed in strings with a space between each mnemonic name and address ControlLogix processors use what in place of addresses as found on RSLogix processors? - correct answer tags In a ControlLogix processor, ladder logic is entered in: Tasks, Routines, or Programs - correct answer routines Define the term network. - correct answer A group of connected logic elements used to perform a specific function .A network also constitutes one rung of a ladder diagram that starts at the left rail and ends at the right rail Explain two advantages of wiring the holding contacts to an input module and then programming the holding contact address into the PLC program - correct answer An overload condition will open the motor coil circuit independent of software .The motor will still be protected from overload condition if controlled from an external bypass means, and motor starter coil can not be energized until the overload relay is manually reset List two ways that holding contacts can be programmed. - correct answer Logical and Discrete