Siemens Level 1 Exam
An 8-bit binary counter has to count balls going into a box from a conveyor belt. A sensor detects the passing of a ball. If it has counted one hundred balls, the binary value of the counter is...
0110 0100
The maximum number of outputs allowed per network in a Step 7 program is...
1
If a given memory unit consists of 2,400 bytes the memory capacity would be rated...
2,400 bytes * 8= 19,200 bits
The largest number that can be represented with eleven binary bits is...
2047
A system contains two identical circuits operating in parallel. As long as both are operating properly, the outputs of both circuits are always the same. If one of the circuits fails, the outputs will be at opposite levels. To indicate the failure, the outputs of the circuits are connected to the inputs of...
?
The status bit of switches and pushbuttons connected to a PLC input module are stored in the...
?
The binary number 1010 0111 1100 0101 can be written in hexadecimal as...
A7C5
What is the basic function of a PLC?
Accept inputs, make logical decisions, and send outputs
The Central Processing Unit (CPU) ...
Accepts inputs, makes decisions provided by the program, and sets outputs.
Field devices refer to...
All kinds of sensors and actuators that are physically wired to PLC input/output modules.
A device used to convert a binary number to a 7-segment display format is...
Decoder
What is true about a NAND gate?
If all inputs are 0, the output will be 1. If one or more inputs are 0 the output will be 1.
By which system does the CPU communicate with input and output modules located on the same rack?
Interface module - IM
What is the basic difference between a PLC and a relay control system?
One uses relay control logic and the other uses programmed instructions.
The PLC program is uploaded from the programming device into the PLC. Into what specific CPU-Memory of the PLC is the program loaded?
Process - image input table
What counter is available in STEP 7?
Up/Down counter
What kind of signal varies continuously?
Variable signal
If you want to know when one or both matching bits in two different words are logic '1' you would use the...
XOR instruction
Branch instructions used to create...
a series of energized output conditions.
A move instruction copies data from...
a source byte to a destination byte
The maximum number of networks allowed in a Step 7 program is...
limited only by the memory size
In PLC operation, a scan is usually a sequential process of...
reading the status of inputs, evaluating control logic, and updating outputs.
Parallel connections of a ladder logic program are typically called...
rungs
In programs that are written in ladder logic, all outputs are represented by...
schematic load device symbols
An imaginary coil that, when energized, will activate a digital output contact looks like...
-( )-
A contact that is usually opened will look like...
-I I-
The conversion of the decimal number 156 to 8421 BCD is...
0001 0101 0110
