Routine
__________ is the user text associated with the rungs and instructions of a controller project that explains the operation of that item.
PROJECT DOCUMENTATION
Most PLCs have two basic counter instructions: Count Up (CTU) and __________.
COUNT DOWN (CTD)
The Count Down (CTD) instruction __________ the Accumulated value by one each time the rung containing the instruction goes from false to true.
DECREASES
In the __________ method of troubleshooting, the troubleshooter isolates the problem of a system according to whether or not a component could cause the symptom observed.
Symptom and Cause
What is the basic function of a XIO?
Go look for a 0
True/False
DINT supply faults is one of the Seven PLC Faults
False
A counter instruction tag's Done (DN) bit is set when the Accumulated value is great than or equal to the __________ value.
PRESET (PRE)
Count Down (CTD) instructions are usually combined with Count Up (CTU) instructions to form a(n) ___________ Counter.
UP/DOWN
A(n) __________ is a graphical method of troubleshooting that uses block symbols connected by flow lines to show the sequence of steps to follow.
Flowchart
What is the basic function for an OTE?
WRITE "1" FOR TRUE, "0" FOR FALSE
What is the basic function of a XIC?
Go look for a 1
(It really is that simple)
Time-driven sequencing can be used in applications where ___________ is not consistent enough to use limit switches for event-driven sequencing.
ACTUATOR POSITIONING
The Up/Down counter's Done (DN) bit is __________ whenever the Accumulated (ACC) value is greater than or equal to the Preset (PRE) value and reset when the value is less than the Preset (PRE) value.
SET
Troubleshooting a ControlLogix processor requires using the processor's __________ to determine the operating condition of the processor.
Indicator Lights
An XIC is not a(n) _____________?
CLOSED SWITCH
The __________ shows how the machine's devices are wired to the PLC's inputs and outputs.
I/O DIAGRAM
A PLC time-driven sequencing program operates by using a series of timer relays that each control a(n) __________ in the sequence.
EVENT
True/False: Count Down (CTD) instructions are NEVER used alone in PLC programs.
False
though they are rarely use, they are occasionally used.
A flashing red I/O module status (ok) indicator indicates the module has a(n) __________ fault.
Communications
An XIO is not a(n) __________?
Open Switch
PLC routines can use timers as well as __________ to sequence events.
LIMIT SWITCHES
The Count Up instruction increases the instruction tag's __________ value by one each time the rung containing the counter goes from false to true.
ACCUMULATED VALUE
Count Down (CTD) instructions are __________ used alone in PLC programs.RARELYLike the CTU instruction, the CTD instruction uses __________ DINT members in its tag structure.
THREE
If an output device doesn't work even though the corresponding output terminals are energized, the problem is either in the __________ or the interface wiring.
DEVICE
The Emergency Stop function should always be __________ into the power supply of the PLC's output.
Hard Wired