Mitsubishi PLC's TO instruction, FROM instruction and example FX2N-4AD application - Database & Sql Blog Articles

Programmable Package SG-8018CA(SG7050C) 0.67M~170M

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The TO instruction is an instruction to write data from the plc to the added special unit (such as FX2N-4DA) buffer memory (BFM).

TO, TOP: 16-bit continuous execution and pulse execution type instructions

DTO, DTOP: 32 consecutive execution and pulse execution instructions

Programming format of the TO instruction: TO K1 K12 D0 K2

*K1: Address number of special module, can only use value, range: 0---7

*K12: buffer memory start address number of special module, can only use value, range: 0---32767

*D0: source register start address number, can be combined with T, C, D values ​​and bit components such as K4X0

*K2: The number of points transmitted can only be used as a value. Range: 1---32767

The function of the TO K1 K12 D0 K2 command is to write the values ​​of the 16-bit registers D0 and D1 of the PLC to the buffer registers (BFM) #12, #13 of the special unit (or module) N0.1.

1. When the special auxiliary relay M8164 is closed, the data in D8164 is used as the transmission point number.

2. The special auxiliary relay M8028 is in the off state. When the TO instruction is executed, it automatically enters the interrupt disable state. The input interrupt and timer interrupt cannot be executed. Interrupts that occur during this period can only be executed after the FROM instruction has been executed. TO instruction can be used in the interrupt program

3. The special auxiliary relay M8028 is in the closed state. When the TO instruction is executed, the interrupt program is executed if an interrupt occurs, and the TO instruction cannot be used in the interrupt program.

The FROM instruction is an instruction to read the contents of a special unit (such as FX2N-4AD) buffer memory (BFM) added to the PLC to the programmable controller.

FROM, FROMP: 16-bit continuous execution and pulse execution type instructions

DFROM, DFROMP: 32-bit continuous execution and pulse execution type instructions

The programming format of the read command FROM: FROM K1 K29 D0 K2

*K1: Address number of special module, can only use value, range: 0---7

*K29: buffer memory start address number of special module, can only use value, range: 0---32767

*D0: Destination register start address number, which can be combined with T, C, D and bit elements other than X, such as K4Y0

*K2: The number of points transmitted can only be used as a value. Range: 1---32767

FROM K1 K29 D0 The function of the K2 instruction is: Read 16-bit data from the buffer register (BFM) #29, #30 of the special unit (or module) N0.1 and transfer it to the D0 and D1 registers of the PLC.

1. When the special auxiliary relay M8164 is closed, the data in D8164 is used as the transmission point number.

2. The special auxiliary relay M8028 is in the off state. When the FROM instruction is executed, the interrupt is disabled automatically. The input interrupt and timer interrupt cannot be executed. Interrupts that occur during this period can only be executed after the FROM instruction has been executed. The FROM instruction can be used in an interrupt program.

3. The special auxiliary relay M8028 is in the closed state. When the FROM instruction is executed, the interrupt program is executed if an interrupt occurs, and the FROM instruction cannot be used in the interrupt program.

The FX2N-4AD converts the analog signal received by the input channel into a digital unit. The module has four input channels with a maximum resolution of 12 bits.

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FX2N-4AD:

1. The available analog value range is -10V to 10VDC (resolution: 5mV), or 4 to 20mA, -20mA to 20mA (resolution 20μA).

2. The FX2N-4AD and FX2N master units exchange data through the buffer memory. The FX2N-4AD has 32 buffer memories (each of which is 16-bit data).

3. The FX2N-4AD occupies 8 points of the FX2N expansion bus. These 8 points can be assigned as inputs or outputs. The FX2N-4AD consumes 30mA of current from the FX2N main unit or active expansion unit 5V power supply.

The allocation of buffer memory (BFM) is as follows:

*#0: Channel initialization, default value H0000.

*#1---#4: Channel 1---the average number of samples of channel 4 (1---4096), used to get the average result. The default value is set to 8 (normal speed) and 1 for high speed operation.

#5---#8: Channel 1---the average input value of the channel 4 sample number, that is, the average number of samples according to #1---#4, the average value of all samples is obtained.

#9---#12: Channel 1---current value read by channel 4.

#13,#14: Reserved, users cannot change.

*#15: Select A/D conversion speed, set to 0 (default value) to select normal speed (15ms/channel); set to 1 to select high speed (15ms/channel).

#16---#19: Reserved, users cannot change.

*#20: Reset to default and preset. The default is 0.

*#21: It is prohibited to adjust the offset and gain values. The default is (0, 1) allowed state.

*#22: Offset, gain adjustment G4 O4 G3 O3 G2 O2 G1 O1.

*#23: The offset value defaults to 0.

*#24: The gain value defaults to 5000.

#25---#28: Reserved, users cannot change.

#29: Error status.

#30: Identification code K2010.

#31: Disabled.

Buffers with the * flag (eg #0) can be written from the PLC with the BFM write instruction TO. Buffers without the * mark (such as #5) can be read into the PLC using the BFM read command FROM. Definition of offset: The analog input value when the digital output is 0. Definition of gain: The analog input value when the digital output is +1000.

An example is shown in Figure: Channel 1 and Channel 2 are used as voltage inputs. The FX2N-4AD module is connected to position 0 of the special function module. The average is set to 4. The D0 and D1 of the PLC receive the average digital value.

1. Read the identification code compared with K2010. If the identification code is K2010, it means that #p#page title#e#PLC connected module is FX2N-4AD, CMP instruction will close M1 (K2010 is equal to D4).

2. Establish analog input channels #1, #2. The role of #0 buffer is channel initialization. Channel 1 and channel 4 are specified from low to high respectively. The bit is defined as: 0--preset range (-10V to 10V).