
51
BCD (Binary Coded Decimal)
BCD is used to express a decimal digit (0 to 9) using 4 bits. Conversion
of BCD values can be done in hexadecimal calculations.
Flash ROM
It refers to a ROM (EEPROM) that stores programs. Since its contents
can be deleted periodically, it is frequently used for equipments that
deals with programs such as a PLC.
How to use a register
•
R (Relay) register (Can be bit, word or double word)
Indicates the external I/O register that directly connects to the
general I/O module
•
M (Memory) register (Can be bit, word or double word)
An internal bit memory address which supports the relay of logical
operations. It is used as a word or double-word variable for
general calculations and programs.
When the power of the PLC is turned off or the CPU has stopped,
the register value is reset to 0.
•
W (Word) register (Can be bit, word or double word)
Same usage as M registers. The value is preserved after the power
is turned off, but can be cleared by program downloads or special
command words.
Not used as a bit (register only for word use)
•
K (Keep) register (Can be bit, word or double word)
Used for general calculation programs. The value is preserved
after the power is turned off.
•
F (Flag) register (Only process bit)
These bit registers provide special application specific functions to
the programmer of the PLC. They are also used as system control
bits, providing Run/Stop control of the PLC.
•
When a calculation or input value exceeds 65,535 (FFFF)
Use a double word instruction that can store and calculate values
over 65,535 in the K, M, R, and W registers. When a double word
instruction is used, it can represent values up to 4,294,967,295 (2
32
).
•
When you want to reload the contents or values that you worked
today
Use the K and W area. These are preserved unless specifically
erased. The W area is erased by special instructions or program
downloads.
•
When you need numerical expressions such as A+B=C, 34
×
45=D,
A1>C1.
Use the R, M, W, and K area. If you use the R area, you can refer to
and output calculated values in I/O modules.
NOTE
Example: 59 (BCD) = 59 (HEX), 32 (BCD) = 32 (HEX)
Summary of Contents for Samsung NX-CPU700p
Page 1: ...NX700 Series Controller NX CPU700p User Manual ...
Page 78: ...78 Power check flow chart ...
Page 79: ...79 Run check flow chart ...
Page 80: ...80 Error check flow chart ...
Page 82: ...82 External environment check flow chart ...
Page 86: ...86 ...
Page 98: ...98 ...
Page 102: ...102 Decimal Bin Hex BCD Gray Code Cross reference Table ...
Page 104: ...104 ...
Page 121: ......