3 . I ns t r uc ti on Se t3- 2 3Decimal floating point = [constant D0] × 10 [exponent D1 ]Constant D0 = ±1,000 ~ ±9,999Exponent D1 = -41 ~ +35The constant 100 does not exist in D0 because 100 is represented as 1,000 × 10-1. The range ofdecimal floating point is ±1175 × 10-41 ~ ±3402×10+35. The decimal floating point can be used in the following instructions:D EBCD: Convert binary floating point to decimal floating pointD EBIN: Convert decimal floating point to binary floating point Zero flag (M1020), borrow flag (M1021), carry flag (M1022) and the floating point operationinstructionZero flag: M1020 = On if the operational result is “0”.Borrow flag: M1021 = On if the operational result exceeds the minimum unit.Carry flag: M1022 = On if the absolute value of the operational result exceeds the range ofuse.Index register E, FThe index registers are 16-bit registers. There are 16 devices including E0 ~ E7 and F0 ~ F7.F0 E0E0F016-bit 16-bit32-bitHigh byte Low byte E and F index registers are 16-bit data registerswhich can be read and written. If you need a 32-bit register, you have to designateE. In this case, F will be covered up by E andcannot be used; otherwise, the contents in E maybecome incorrect. (We recommend you use MOVPinstruction to reset the contents in D to 0 when thePLC is switched on.) Combination of E and F when you designate a32-bit index register: (E0, F0), (E1, F1), (E2, F2), …(E7, F7)MOV K20E0 D10F0E0 = 8 F0 = 1420 + 8 = 28 10 + 14 = 24Transmission K28 D24The opposite diagram E, F index register modificationrefers to the content in the operand changes with thecontents in E and F.For example, E0 = 8 and K20E0 represents constantK28 (20 + 8). When the condition is true, constant K28will be transmitted to register D24.Devices modifiable: P, X, Y, M, S, KnX, KnY, KnM, KnS, T, C, D.E and F can modify the devices listed above but cannot modify themselves and Kn., e.g. K4M0E0is valid and K0E0M0 is invalid. Grey columns in the table of operand at the beginning page of each
