8 Application Instructions API 100-149 API 125 Operands: S : Device for operation source D : Device for operation result Explanations: 1. See the specifications of each model for their range of use. 2. Flags: M1020 (zero flag); M1021 (borrow flag); M1022 (carry flag) 3. This instruction performs natural logarithm “LN” operation by S : LN ［ S + 1, S ］ = ［ D + 1, D ］ 4. Only positive values are valid for S . When designating D registers, the data should be 32-bit and the operation 5. e D = S .The content in D = ln S ; S = designated source data. should be performed in floating point system. Therefore, S should be converted into a floating point value. 6.
If the absolute value of the result ＞ maximum floating point available, the carry flag M1022 = On. 7. If the absolute value of the result ＜ minimum floating point available, the borrow flag M1021 = On. 8. If the result = 0, the zero flag M1020 = On. Program Example: 1. When M0 = On, convert (D1, D0) into binary floating point and store it in register (D11, D10). 2. When M1= On, use register (D11, D10) as the real number for LN operation and store the binary floating point result in register (D21, D20). 3. When M2 = On, convert the binary floating point (D21, D20) into decimal floating point (D30 Ч 10 [D31] ) and store it in register (D31, D30). M0 M1 M2 Remarks:
For floating point operations, see “5.3 Handling of Numeric Values”. DVP-PLC Application Manual 8-40 Mnemonic Operands Function D LN P Natural Logarithm of Binary Floating Point Type OP Bit Devices Word Devices Program Steps X Y M S K H KnX KnY KnM KnS T C D E F DLN, DLNP: 9 steps S * * * D * PULSE 16-bit 32-bit EH3 ES EX SS SA SX SC EH SV EH3 SV2 EH3 ES EX SS SA S X SC EH SV ES EX SS SA SX SC EH SV SV2 SV2 0 RST M1081 DFLT D0 D10 DLN D10 D20 DEBCD D20 D30