PLC practice test
A CTU will increment the accumulated value each time the rung goes from true to false, while a CTD will
decrement the accumulated value each time the rung goes from false to true. - Answer-False
A PLC is controlling a continuous loading application (pick and place) sequence. What type of signal
would be best to activate each step of the sequence? - Answer-an input sensor
A hard-wired MCR is used to - Answer-disable all outputs for safety
A PLC output will be true when - Answer-a 1 is placed in the memory location for that output,
a force is applied to the output,
when all the inputs on the rung are true
Controller (processor) faults cause the majority of PLC problems. - Answer-False
How many projects (i.e. programs) can be running in the PLC at one time? - Answer-1
If a rung is placed in the program with no inputs and one output, the rung will generate an error. -
Answer-False
If a rung is placed in the program with one input and no outputs, the PLC will generate an error. -
Answer-True
If a tag has the property Local it is ____________ defined - Answer-module
, Place the different operations of the PLC in the correct order: - Answer-Examine inpiuts, Perform logic,
update outputs.
An output address/tag for a single physical terminal location can only be used ONCE in a program. -
Answer-True
One physical input device can be referenced by several different input instructions. - Answer-True
In an time-driven operation using non-retentive timers, adding more inputs to the operation will mean
adding more timers as well. - Answer-False
In an event-driven sequence, adding more steps means adding more inputs. - Answer-True
If the normally closed contacts of a switch are wired to a PLC input module, when the switch is
unoperated, if using an XIC in the PLC program, the instruction will be highlighted (assume the
programming device is online with the PLC). - Answer-True
If the normally closed contacts of a switch are wired to a PLC input module, when the switch is
unoperated voltage will be measured at the input terminal. - Answer-True
If the normally closed contacts of a switch are wired to a PLC input module, when the switch is
unoperated the status light on the PLC module will be on. - Answer-True
What is the main purpose of an I/O diagram? - Answer-to show the physical connections from the PLC
modules to electrical devices
What is contained in the PLC Project? - Answer-Tasks
Programs
Routines
A CTU will increment the accumulated value each time the rung goes from true to false, while a CTD will
decrement the accumulated value each time the rung goes from false to true. - Answer-False
A PLC is controlling a continuous loading application (pick and place) sequence. What type of signal
would be best to activate each step of the sequence? - Answer-an input sensor
A hard-wired MCR is used to - Answer-disable all outputs for safety
A PLC output will be true when - Answer-a 1 is placed in the memory location for that output,
a force is applied to the output,
when all the inputs on the rung are true
Controller (processor) faults cause the majority of PLC problems. - Answer-False
How many projects (i.e. programs) can be running in the PLC at one time? - Answer-1
If a rung is placed in the program with no inputs and one output, the rung will generate an error. -
Answer-False
If a rung is placed in the program with one input and no outputs, the PLC will generate an error. -
Answer-True
If a tag has the property Local it is ____________ defined - Answer-module
, Place the different operations of the PLC in the correct order: - Answer-Examine inpiuts, Perform logic,
update outputs.
An output address/tag for a single physical terminal location can only be used ONCE in a program. -
Answer-True
One physical input device can be referenced by several different input instructions. - Answer-True
In an time-driven operation using non-retentive timers, adding more inputs to the operation will mean
adding more timers as well. - Answer-False
In an event-driven sequence, adding more steps means adding more inputs. - Answer-True
If the normally closed contacts of a switch are wired to a PLC input module, when the switch is
unoperated, if using an XIC in the PLC program, the instruction will be highlighted (assume the
programming device is online with the PLC). - Answer-True
If the normally closed contacts of a switch are wired to a PLC input module, when the switch is
unoperated voltage will be measured at the input terminal. - Answer-True
If the normally closed contacts of a switch are wired to a PLC input module, when the switch is
unoperated the status light on the PLC module will be on. - Answer-True
What is the main purpose of an I/O diagram? - Answer-to show the physical connections from the PLC
modules to electrical devices
What is contained in the PLC Project? - Answer-Tasks
Programs
Routines
