FX1S-30MR-ES/UL MITSUBISHI, FX1S-30MR-ES/UL Datasheet - Page 116

• Manufacturer Part Number: FX1S-30MR-ES/UL
• Description: PLC, 16 IN, 14 RELAY OUT, 110V/2
• Manufacturer: MITSUBISHI

Specifications of FX1S-30MR-ES/UL

• No. Of Analogue Inputs: 16
• No. Of Analogue Outputs: 14
• Ip/nema Rating: IP10
• Approval Bodies: CE, CUL, UL
• External Depth: 49mm
• External Length / Height: 90mm
• External Width: 60mm
• Mounting Type: Panel

4.14.4
FX Series Programmable Controllers
Two’s Compliment
Programmable controllers, computers etc, use a format called 2’s compliment. This is a
mathematical procedure which is more suited to the micro processors operational hardware
requirements. It is used to represent negative numbers and to perform subtraction operations.
The procedure is very simple, in the following example “15 - 7” is going to be solved:
Step1: Find the binary values (this example uses 8 bits)
Step2: Find the inversion of the value to be subtracted.
Procedure : invert all 1ís to 0ís and all 0ís to 1’s.
Step3: Add 1 to the inverted number.
Procedure: add 1 to the right hand most bit. Remember this is binary addition hence, when a
value of 2 is obtained 1 is moved in to the next left hand position and the remainder is set to 0
(zero);
Step4: Add the answer to the number the subtraction is being made from (i.e. 15).
Procedure: Remember 1+1 = 0 carry 1 in base 2 (binary).
The “(1)” is a carried “1” and is ignored as this example is only dealing with 8 bits.
Step 5: Convert the answer back.
00001000 = 8
The answer is positive because the MSB (the most left hand bit) is a 0 (zero). If a quick mental
check is made of the problem it is indeed found that “15-7 = 8”.
In fact no subtraction has taken place. Each of the steps has either converted some data or
performed an addition. Yet the answer is correct 15 - 7 is 8. This example calculation was
based on 8 bit numbers but it will work equally well on any other quantity of bits.
15
7
7
Inverted 7 =
This result is actually the same as the negative value for 7 i.e. -7.
Inverted7
Additional1
Answer
Original value15
Answer found in step3
Solution
=
=
=
11111000
00000001
11111001
00001111
00000111
00000111
11111000
(1) 00001000
00001111
11111001
Devices in Detail 4
4-42