Specification Of Digits For Bit Devices (Kn[ ]***) - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
5.4

Specification of Digits for Bit Devices (Kn[ ]***)

Handling of bit devices
Devices which handle only the ON/OFF information such as X, Y, M and S are called bit devices.
On the other hand, devices handling numeric values such as T, C, D and R are called word devices.
Even bit devices can handle a numeric value when they are combined. In this case, the number of digits Kn
and the head device number are combined.
The number of digits is expressed in 4 bit units (digits); K1 to K4 are used for 16-bit data, and K1 to K8 are
used for 32-bit data.
For example, "K2M0" indicates two-digit data expressed by M0 to M7.
0 1 0
Sign bit (0 = Positive, 1: Negative)
M15 M14 M13
Sign bit (0 = Positive, 1: Negative)
0 0 0
When 16-bit data is transferred to K1M0 to K3M0, the highest-order bits are not transferred due to insufficient
data length.
32-bit data is transferred in the same way.
When the number of digits specified for bit devices is K1 to K3 (or K1 to K7) in a 16-bit (or 32-bit) operation,
the insufficient high-order bits are always regarded as "0". It means that such data is always positive.
M 0
FNC 19
BIN
A bit device number can be specified arbitrarily, but it is recommended to set the least significant digit to "0"
for X or Y. (In other words, it is recommended to specify "X000, X010, X020 ... Y000, Y010, Y020 ...")
For M and S, multiples of "8" are ideal, but it is recommended to specify "M0, M10, M20 ..." to prevent
confusion.
Specification of consecutive words
A series of data registers starting from D1 means "D1, D2, D3, D4 ....."
In the case of word devices with digit specification, when such word devices are handled as a series, they are
specified as shown below:
• K1X000,
• K2Y010,
• K3M0,
• K4S16,
Use the above devices in digit units so that devices are not skipped.
When "K4Y000" is used in a 32-bit operation, the high-order 16 bits register as "0".
It is necessary to use "K8Y000" when 32-bit data is required.
164
1 0 1 0
Do not change
M12 M11 M10 M9
0 0 0 0
Two-digit BCD data expressed by X004 to X013 is converted into
K 2X004 D 0
binary data, and then transferred to D0.
K1X004, K1X010,
K2Y020, K2Y030 .....
K3M12, M3M24,
K4S32, K4S48 .....
5 How to Specify Devices and Constants to Instructions
1 0 1 0 1
D 0
Transferred
K2M0
0 1 0 1
M8 M7 M6 M5 M4
Transferred
D 1
0 0 1 0 1
K1X014 .....
K3M36 .....
5.4 Specification of Digits for Bit Devices (Kn[ ]***)
0 1 0 1
Low order
0 1 0 1
M3 M2 M1 M0
Low order
0 1 0 1