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S7-300 PLC CPU Panel features

1, load power supply module

Load power supply module is used to convert AC 220V power supply DC 24V, for use by the CPU and I/O module and other modules.

2, backup battery

Backup battery in the PLC is the role of power, to ensure the normal operation of the real-time CPU clock, and you can save a user‘s programs and data (in RAM). Some lower-end CPU because there is no real time clock, there is no backup battery.

3, DC 24V terminals

CPU outputs a DC 24V,L+ DC 24V anode and cathode respectively and m. Can be used as a CPU switch signal input or external power components.

4, mode selector switch

Mode selector switch used to select the operation mode of the CPU. The switch is a key switch, altering the way it needs to insert the key to prevent unauthorized people from changing the CPU operation mode.

Mode selector switch position as follows:

(1) RUN-P (runprogram) location: CPU not only execution of the program can also read and modify procedures and altering the way;

(2) RUN (run) position: CPU execution of the program can read the program, but you cannot modify the program;

(3) STOP (stop) position: CPU does not perform procedures, can read and modify procedures;

(4) the MERS (MEMORY CLEARED) location: can reset the memory, the CPU back to the initial state. This position cannot be maintained, when after the release and return to the STOP position.

5, status and fault led

(1) SF (system fault indicator, red): CPU hardware failure or a software error occurred frequently;

(2) the BATF (battery, red): low battery voltage or no batteries are often lit;

(3) DC 5V (+5V power supply, green): CPU and S7-300 bus +5V power supply normal bright at times;

(4) FRCE (mandatory instructions, yellow): at least one I/O is often by force;

(5) RUN (running instructions, green): CPU in RUN run as often, when booting with the 2Hz frequency of shiny, shiny HOLD State of 0.5Hz frequency;

(6) STOP (stop instructions, yellow): CPU at a STOP, HOLD the State often; request a memory reset blinking at a frequency of 0.5Hz being reset to 2Hz frequency flicker;

(7) the BUSF (bus fault indication, red): Profibud-DP interface to hardware or software failure is often light.

6, memory card

Memory card when the electricity was used to save user programs and data, you can extend the storage capacity of the CPU.

7, MPI interface

MPI interface for CPU and other PLC, PG/PC (PG/PC), OP (operator interface) via MPI network communications.

8, front connector

Front connector is used to connect sensors and actuators to the signal module, front cover (9).

Siemens S7-300PLC OB tissue

OB73 redundancy error OB
When the first redundancy fault-tolerant S7 connection is lost, the h CPU operating system called OB73 (fault-tolerant only S7 communication S7 connection) if other fault-tolerant S7 connection redundancy is lost, then there will be no more OB73. Until for all S7 connection is restored after redundancy with fault-tolerant features, will there be other OB73. If there is a launch event and OB73 no programming, CPU not to STOP mode.

Error OB80 time tissue
Whenever error executing OB, S7-300 CPU operating system called OB80. Such errors include: beyond the cycle time, implementation of the OB appears to confirm that the error startup time, ahead of time, and OB is skipped, CiR recovery RUN mode. For example, if, after a previous call to the cyclic interrupt OB started event, while the same OB remained in place at this time, the operating system will call OB80. If OB80 has not been programmed, the CPU will be converted into STOP mode. You can use SFC 39 to 42 disable or re-enable time delays and errors OB.

OB81 power error tissue
As long as the event that triggered by error or malfunction occurs, and this error or fault with the power supply (only on S7-400) or backup battery (when entering and leaving), S7-300 operating system call CPU OB81. In the S7-400, if the battery test function has been activated using the BATT.INDIC switch, only OB81 is only invoked in case of battery failure. If OB81 without programming, the CPU is not to STOP mode. You can use SFC 39 to 42 disabled or delayed, and re-enable the power error OB.

OB82 diagnostic interrupt organization block
If the module has a diagnostic function (for which you have enabled diagnostic interrupt) error is detected, it will output a diagnostic interrupt requests to the CPU (when entering and leaving). The operating system called OB82. OB82 local variables contain the logical base and fourbyte module fault diagnosis data (see table below). If OB82 has not been programmed, the CPU to STOP mode. You can use SFC 39 to 42 disabled or delayed, and enable diagnostic interrupt OB again.

OB83 insert/remove module interrupt organization block
In the following case, the CPU operating system called OB 83:
1, insert/remove configuration module
2, modify the module parameters in STEP 7, and after the download changes to the CPU at run time
Can use SFC 39 to 42 delayed insert/enable/disable/delete interrupt OB.

OB84CPU hardware organization
In the following cases, CPU OS will invoke OB84:
1, after a memory error has been detected and corrected
2, S7-400H: If two redundant links between CPU performance degradation
SFC 39 to 42 can be used to disable CPU hardware error or delay OB, and then enable it again.

OB85priority error tissue
Whenever one of the following events occurs, CPU‘s operating system is called OB85:
1, OB not yet loaded (except for OB81) initiated the event.
2, the operating system error accessing the module.
3, the system image I/O access errors occur during the update process (if configuration reasons, does not prohibit OB85 calls).

OB86 rack failure tissue
As long as the distributed I/O (PROFIBUS DP or PROFInet IO) was detected in the Central extension frame (without the S7-300), the DP master station or station (when entering the event and leave events), the CPU operating system called OB86. If OB86 has not been programmed, when this type of error has been detected, CPU to STOP mode. Use SFC 39 to 42 disabled or delayed, and re-enable the OB86.

OB87 communication error tissue
As long as the event that caused by a communication error occurs, CPU operating system called OB87. If OB87 has not been programmed, CPU not to STOP mode. You can use SFC 39 to 42 disabled or delayed, and re-enable communication error OB.

OB 88 processing interrupt OB
Block after the execution was aborted, CPU operating system called OB 88. Causing this disruption may be:
1, the nesting depth of the synchronization error is too large
2, block calls (u stack) nesting depth is too large
Error 3, assign the local data
Failure to OB 88 programming and program execution is aborted, the CPU enters STOP mode (event ID W#16#4570). If you suspended the program priorities 28 block is executed, the CPU enters STOP mode. By SFC 39 to 42 disabled enabled, delay and interrupt OB.

OB121 programming error tissue
As long as the same processrelated errors in the event, CPU‘s operating system is called OB121. For example, if a user called has not been loaded into the CPU block, will be called OB121.

OB122I/O access error tissue
As long as access to module data error, CPU‘s operating system is called OB122. For example, when you access data on the I/O module, CPU read error is detected, the operating system calls OB122.

Siemens new PLC program, data storage cards

MMC card is the new Siemens PLC program, data storage, and present several PLC should be used for the following products:

Order product name
6ES7 314-1AF10-0AB0 new CPU 314
6ES7 new CPU 315-2AG10-0AB0 315-2DP
6ES7 312-5BD00-0AB0 CPU 312C
6ES7 313-5BE00-0AB0 CPU 313C
6ES7 313-6CE00-0AB0 CPU 313C-2DP
6ES7 313-6BE00-0AB0 CPU 313C-2PTP
6ES7 314-6CF00-0AB0 CPU 314C-2DP
6ES7 314-6BF00-0AB0 CPU 314C-2PTP
6ES7 613-1CA00-0AE3 C7 613
6ES7 635-2EC00-0AE3 C7 635 OP
6ES7 635-2EB00-0AE3 C7 635 OP
6ES7 151-7***-0AB0 ET200S with CPU
Note: the above product order number may be slight adjustments in product hardware and software upgrades, product characteristics product name shall prevail.

1. In ordered above products Shi, PLC itself not with MMC card, so to normal using PLC, you must according to you project actual needs ordered a size applies of MMC card, if you of PLC Shang not insert MMC card, you is cannot will STEP7 in the of program and data download down of, while you should note, cannot charged plug pulled MMC card, or will lost program or damaged MMC card.

2. In the Simatic Manager, select Download a block, then the block is downloaded to the MMC card, if you select in the tree diagram on the left of the window Block folder to download, all chunks are downloaded to the MMC card, MMC existing information will be overwritten, and the number of read and write data to the MMC card or download the program without restrictions.

3. Except the CPU integrated in the SFB/SFCs blocks of MMC among other pieces can be deleted online.

4. For some CPU, new MMC card (6ES7 953-XXX10-0AA0) replace the old version of the MMC card (6ES7 953-XXX00-0AA0), PLC’s OPERATING SYSTEM needs to be upgraded. Upgrades require the use of PG (6ES7798-0BA00-0XA0) or a programmer with USB port (6ES7792-0AA00-0XA0), through STEP7 MANAGER menu feature in Windows PLC/UPDATE OPERATING SYSTEM” will be CPU_HD. UPD files written to the MMC card, CPU_HD. UPD files can be downloaded at www4.ad.Siemens.de get.

5. MMC card as CPU of Mount memory (Load Memory), in for you of CPU selection MMC of when, we recommends you by selected of MMC card must to is greater than is equal to you by selected of CPU work memory of size (work memory), best than work memory big some, but if you of application in the, PLC work Shi to using large of process data, history data, formula data, or control process in the exists more of user program block, and STEP7 function blocks (such as FB41, FB42, and so on), it is recommended that the MMC card using 2-8M, but please note that only 314, 315-2DP, C7 series PLC supports MMC card 8M.

6. MMC card is loaded in-memory, so it is not able to read directly from your PC configuration software in data values on the MMC card (data in the DB), the configuration screen is read PLC data in the RAM memory.

7. Siemens PLC, Siemens must be used on a dedicated MMC cards as listed in the following table, you cannot use the digital camera, mobile phone or PDA and other digital products using genericMMC card.
The order numbers for MMC cards are in the following table:
Micro Memory Card / S7-300 Order number
64 Kbytes                 6ES7 953-8LF11-0AA0
128 Kbytes               6ES7 953-8LG11-0AA0
512 Kbytes               6ES7 953-8LJ11-0AA0
2 Mbytes                  6ES7 953-8LL11-0AA0
4 Mbytes                  6ES7 953-8LM11-0AA0
8 Mbytes                  6ES7 953-8LP11-0AA0

Siemens PLC analog module usage questions

S7-200 analog input module (EM231,EM235) addressing

Each analog expansion module, sorted by extension modules in the order, in which the analog input and output according to different sorting, respectively. Analog data format is one word, so the address must begin with an even number of bytes, precision 12-bit; analog values with the value 0-32000. Input format: AIW[a starting byte address] AIW0 output formats: AQW[a starting byte address] AQW0 each analog input module, module address is fixed in the order, the order to the rear. Example:: AIW0,AIW2,AIW4……, AQW0,AQW2 … ….

At least two channels per analog expansion module, even if the first module has only one output (AQW0 EM235 has only an analog output), the second analog output modules address should also AQW4 to start addressing, and so on.

2. connect the sensor to S7-200 analog input module (EM231,EM235) what are the points for attention?

Analog input module can set the dip switches to different ways of measuring (voltage and current). Module switch settings apply to the entire module, a module can only be set to a measuring range and switch to take effect only after the electricity back on. Input at the same time can only be set to a range and the format, that is, the same input range and resolution.

EM235 is the most commonly used analog expansion module, it implements 4channel analog input and 1 analog output. EM235 analog expansion module wiring method for voltage signals, by positive and negative direct access to X+ and X-; for the current signal, RX and X+ after the short access current input signal + side; channel X+ and X-are not connected sensor shorted.

Note: in order to avoid the commonmode voltage, m end with all signals end to be connected, not connected sensor channels to be shorted. When analog input PLC received a change in very unstable when, for one reason: you may use a self-powered sensor power supply or isolated, both power supply not connected to each other, so the resulting bounce of a high commonmode voltage, affects the analog input value. The second reason: analog input module wiring may be too long or bad insulation. Solution: 1. connect sensor input negative terminal with modules on the public m-side to compensate such fluctuations. (Note: prior to determine if this is the only connection between the two power supplies. If a connection already exists, when added public connection may have an extra compensating current.

When the analog input PLC receives a signal change is slow, this could be you use filters, can be reduced by filtering samples, or cancel the analog filtering solution.

3. EM235 can be used for heat resistance temperature measurement problem?

EM235 module is not used in connection with the thermal resistance measurement temperature, barely used risk failure.

4. EM235 input to calibrate:

Analog input module input calibration before use. Enter calibration prior to shipment, if the OFFSET and GAIN potentiometer is readjusted input calibration is required. The steps are as follows:

A, cut off the power supply module, select the desired input range.

B, connect CPU and power supply modules, the module stability for 15 minutes.

C, a transmitter, a voltage source or current source, the zero value signal applied to an input terminal.

D, read the appropriate input channel measurement value in the CPU.

E and adjust the OFFSET (offset) potentiometers until it reads zero, or need numeric data values.

F, received a full scale signal input terminals, read out the value sent to the CPU.

G, adjust GAIN (gain) potentiometers until reads 32000 or need numeric data values.

H and, if necessary, repeat the offset and gain calibration process.

5. the conversion of the analog values, and the a/d conversion:

Assuming that analog standard signals are A0-Am (such as 4-20mA), after a/d conversion values for D0-Dm (such as 6400-32000), analog standard signals are A,A/D after the corresponding value of d, because it is a linear, function A=f (d) can be expressed as a mathematical equation:


According to the formula d value can be easy to calculate a value. This equation inverse transform, D=f draw function (a) mathematical equation can be expressed as:


To quote an example, a case study of S7-200 and 4-20mA, a/d conversion, we get a value of 6400-32000, the A0=4,Am=20,D0=6400,Dm=32000, into the equation is obtained:


Hypothesis corresponds to the analog and AIW0, when the value of AIW0 is 12800, the corresponding analog signal is 6400×16/25600+4=8mA.

As another example, a temperature sensor,10-60 corresponds to 4-20mA, and t represents the temperature value, AIW0 PLC analog sampled values according to type directly into the draw:


Can t displayed temperature value.

Conversion of the analog values, and the a/d conversion more difficult to understand, that paragraph several times, combined with the examples, you will understand. To make it easy for you to understand, let me give you an example:

A pressure transmitter, when the pressure reaches full scale 5MPa, pressure transmitter 20mA,AIW0 is the output current value is 32000. Visible/MA A/D that corresponds to the value of 32000/20, when measuring the pressure 0.1MPa, pressure transmitter should be current as of 4mA,A/D (32000/20) X4=6400. It follows that the AIW0 value to the actual pressure value (units KPa) is calculated as:

The value of VW0 = (value of AIW06400) (5000-100)/(32000-6400) +100 (units: KPa)

Programming examples

Instance demo that you can form a small analog programming. CPU in this instance is CPU222, with only an analog extension EM235 module, the first channel of the module to connect a 4-20mA transmitter output temperatures display instrument, the instrument‘s range is set to 0-100, or 0 degrees when output 4mA,100 20mA output. Platinum resistance temperature display instrument input connect a 220 Ohm variable potentiometer, simple programming are as follows:

Temperature display value = (AIW0-6400)/256

Compile and run the program, the watcher, the VW30 temperature value is displayed, control instrument display values are the same.

The difference between Siemens PLC and S7-300 S7-200, S7-400

The main class is one of the programmable logic controller and module difference was S7-200 belonging to the basic entry level, while S7-300 and S7-400 relative to the use of higher-end. Siemens plc is the serial number of the product.

—->S7 200: in the electric control system for small, focused on logical control;
—->S7 300: for larger systems, can realize the complexity of process control, such as PID, PWM, etc;
—->S7 400: used for large scale control system, mainly redundancy control.

200 belongs to small machine, 300 belongs to medium machine, minicomputer is multifunctional machine, will all function combined in with, it of control scale for maximum 512 points, CPU of operation processing speed than in the mainframe fast, minicomputer more for overall type of, extended module up can added 8 block, applies Yu small equipment, price high; in the mainframe structure is module of of, up can added more than 300 more block extended module, in the mainframe hardware more your, cost high, but its operation processing speed fast, has is strong of communications function, Mainly used in large-scale production line, such as the chemical industry, paper industry, steel industry, car production line, air conditioning, sewage treatment, and mainframes in the Siemens 300 and 400 in China, Siemens stable performance, network communication is powerful, simple, and cost-effective.

And hardware differences:

(1) major S7-300/400 more modular, S7-200 series is integral, CPU module, the I/O module and the power supply module in a module, called CPU modules and S7-300/400 series, from the power supply, I/O,CPU is a separate module. But that misleading 200 series cannot be extended, in fact, 200 series can also be extended, bought the CPU module is integrated with the merely functional, some smaller systems do not require additional custom modules, 200 series modules also have signaling, communication, control and other modules.
(2) to rack 200 series no concept, called Guide; in order to facilitate control, 300/400 series module was mounted on a rail, called a rack, is an extended frame corresponding to the Central rack, rack also is reflected in the software.
(3) on the same rack 200 series module by module directly above the data connectors contacts; and 300/400 are at the bottom of the ubus connector.
(4) 300/400 series I/O input is connected to the front connector on the, on the module front connector attached to the signal, and is not directly connected to I/O signals on the signal module so that you can replace signaling modules without rewiring.
(5) 300/400 series CPU with PROFIBUS (PROFIBUS is an international. The open. Not dependent on the device manufacturer‘s fieldbus standard) interfaces.

Second, software differences:
(1) STEP7-Micro/WIN32 for 200 series software 300/400 use STEP7 software, with the Micro and without the difference is quite obvious.
(2) there are three programming languagesof the 200 series statement list (STL), ladder diagram (LAD), function block diagram (FBD); 300/400 series in addition to the three, but also has structured control language (SCL) and graphic language (S7 graph).
(3) 300/400 software features provide a number of blocks of data to each functional block (Block-FB), called Instance.
(4) 300/400 can’t feel free to customize the Organization Block and the sub-routine and Interrupt routine, now the OB1 self-centered, nothing the system will call it, the rest of what became FB-Block and FC-, others are predefined system, System s to them (SFB and the SFC) defined his identity.
(5) 300/400 are provided in the accumulator (ACCU) and status word register, Diagnostics buffer.

S7-300/400PLC pulse method

Method one: CPU clock memory

CPU in the hardware configuration properties Cycle/Clock Memory in the Clock Memory setting the Memory Byte, you can look at to help, each one having a fixed frequency Propreties window click on the Cycle/Clock Memory (loop memory/clock) tab, you can set the Scan cycle monitoring time ( Scanning cycle monitoring time in MS), the default value is 150ms. If the actual cycling scanning time exceeds the set value. CPU will enter STOP mode. Scan cycle Load from Communication used to restrict the traffic handling as percentage of scanning cycle, the default value is 20%
Clock pulses are available for user programs using a square wave signal with duty cycle 1:1, one byte of memory every clock corresponds to one pulse is as follows:
Byte                          Bit7    Bit6  Bit5 Bit4   Bit3 Bit2 Bit1 Bit0
Frequency (Hz)         0.5    0.62    1   1.25     2    2.5    5   10
Period (seconds)      2         1.6     1    0.8    0.5   0.4    0.2  0.1


If to using clock pulse, first to selected “Clock Memory’ (clock memory) option, then set clock memory (m) of byte address. assumed set of address for 100 (that MB100), has Shang table known, M100.7 cycle for 2s, if with M100.7 of often open of touch points to control Q0.0 of coil, Q0.0 will to 2s of cycle flashing (bright 1s, out 1s).

OB85-Call up at I/O access error changes to the system used to set CPU process image I/O access errors that occur when the response If you want to call OB85 when an error occurs, it is recommended that select Only for incoming and out going error (and only errors disappear), as opposed to On each individual access (individual access), Does not increase the scanning cycle time.

Method two: write your own delay procedures and set the delay time, when the time comes when executing a stored procedure call, which under the influence of program cycle time, is not particularly accurate, if it is under less stringent conditions this method can be used.

Method three: using interrupt organization block break on to achieve, such as in OB35 calls a stored procedure, implement store, this method is more accurate.

Method four: SFC1 reads the CPU clock, by a clock realized intervals are calculated as the difference of the value stored. (This method S7-200 from those I do not write the third method similar to this programming method)

Method five: interval such as if you use an external trigger signal, also by means of hardware interrupts.


PLC properties

1. Storage capacity
Storage capacity refers to the user program memory capacity. User program memory capacity, you can develop complex programs. Generally, small PLC user memory capacity for thousands of words, and mainframe user memory capacity of up to tens of thousands of words.

2. I/O points
Input/output (I/O) points is acceptable to the PLC the sum of the input signal and the output signal, an important indicator of performance is a measure of PLC. More I/O points, external input devices and output devices, the more controlling greater scale.

3. Scan speed
Scan speed refers to the speed of PLC user programs, an important indicator of performance is a measure of PLC. General scan 1K the Word user time required by the program to measure speed, usually in units of ms/K. PLC user‘s manual General given the implementation of the directive in time, you can perform the same operation using PLC time, measured and slow scanning speed.

4. Function and number of instruction
Instruction function of intensity, quantity is also important index to measure performance of PLC. Number of programmed instruction more powerful, more PLC and control more powerful, more simple and convenient user programming is, the more complex control tasks.

5. Number and type of internal components
At the time of preparation of the PLC program, requires the use of a large number of internal components to store variables, intermediate results, data, time count, module settings and a variety of flags and other information. The types and quantities of these components more PLC‘s ability to store and handle all kinds of information is.

6. Special function unit
Special types of functional units and functional strength is an important indicator for measuring PLC products. In recent years various PLC manufacturers attach great importance to development of special function unit, special function unit types growing more powerful, PLC control functions has expanded.

7. Scalability
Extended capabilities including I/O point number extension of the PLC, storage capacity extension, networking extension, expansion of the various functional modules, and so on. When choosing a PLC, often need to consider scalability PLC.

Difference between transistor outputs of the PLC and relay output

Relays are mechanical components have life, transistors are electronic components, only the age, no usage limits. Relay switching times per minute is also limited, and transistors are not. Transistors also have high current, such as 5A above.

1. the load voltage and current type

Type of load: transistor can only bring a DC load, and relays with AC and DC load can be.

Current: current maximum 0.75A relays up to 2 a.

Voltage: transistor can be connected with DC 24V (General maximum is about 30V DC relay can take maximum 30V DC 24V or AC 220V).

2. load capacity

Transistor with load capacity is less than the relay load capacity when the transistor is used, sometimes adding other things to drive a large load (such as a relay, solid state relays, etc).

3. transistor overload capacity is less than the relay overload capacity

In General, when there is a large impact current situation (such as a light bulb, inductive load, etc), transistor overload capacity is small, requires Derating more.

4. in transistor response times faster than relays

Relay output-type theory is a CPUdriven relay coil, contact absorbs, driven by external power supply by closing the contact external load, the open drain leakage current is zero, slow response time (10ms).

Transistor output-oriented principle is the CPU by coupling the transistor switching to control external DC loads, faster response time (about 0.2ms or even smaller). Transistor outputs are generally used for high speed output, such as servo/stepper, used for high frequency output.

5. rated working cases, relay switching time of life, the transistor aging not only limited to use

Relays are mechanical components have life, transistors are electronic components, only the age, no usage limits. Relay switching times per minute is also limited, and transistors are not. Transistors also have high current, such as 5A above. Is transistor output when followed by a relay, paying special attention to polarity of relay coil (coils in general are connected with a protection diode or led on), or you will burn out transistor.

Special features of Mitsubishi FX series PLC modules-data communication module

PLC communication module is used to complete with other PLC and other communications between intelligent control device or computer. Following simple FX series communication function expansion board, adapter and communication modules.

(1) communication standard connection expansion board FX2N-232-BD FX2N-232-BD is RS-232C transmission PLC interface with other equipment. Such as PC, barcode readers or printers. Can be installed inside the FX2N. The maximum transmission distance is 15 m, maximum baud rate for 19200bit/s, PLC running status monitoring using special software, and can also be transmitted from the PC to the PLC program.

(2) traffic on the interface module FX2N-232IF FX2N-232IF connected to the FX2N series PLC can be achieved with other devices with RS232C interface for fullduplex serial communications. For example, PC, printers, bar code reading and so on. FX2N series FX2N-232IF modules can connect up to 8 blocks. Use the FROM/TO command to send and receive data. Maximum transmission distance of up to 15 metres, maximum baud rate for 19200bit/s, occupying 8 I/O point. Data length and serial communication baud rate can be set by a special data register.

(3) expansion board FX2N-485-BD FX2N-485-BD-for RS-485, as a way of communication. It can be applied to data transfer without agreement. FX2N-485-BD at the time of the original agreement, as a way, using RS instruction in personal computers, barcode reader, printer, data transfer between. Transmit the maximum transmission distance of up to 50 metres, maximum baud rate for 19200bit/s. Each of the FX2N series PLC can be fitted with a FX2N-485-BD Communications Board. Apart from the use of this communication Board communication with the computer, but it can also be used to achieve two parallel between FX2N series PLC.

(4) communication expansion board FX2N-422-BD FX2N-422-BD to RS-422 traffic. On the connections of the FX2N series PLC, and as a tool for programming or control a port. This interface is available outside of the PLC connected to PLC devices, data storage unit, and human-machine interface. FX2N-422-BD can be used to connect two data storage unit (DU) or DUseries unit and a programming tool, but one can only connect a programming tool. Every basic unit can be connected to a FX2N-422-BD and cannot be used with FX2N-485-BD or FX2N-232-BD.

(5) the interface module MSLSECNET/MINI

Use MSLSECNET/MINI interface module, series PLC of FX series PLC can be used as a local control station, constitute a distributed control system

Mitsubishi PLC password settings

Passwords can limit set PLC programming tool, display module, interface to read and write procedures, monitoring, change the current values, and so on, to protect programs or restrict the operator‘s procedures for monitoring purposes.

Mitsubishi FX series PLC password set way: will PLC power, and through programming cable and computer connection, in programming software GX-DEVELOPER in the followed by select “online”–“login key word”–“new login”, in pop-up of dialogue box in the of “key word” Hou of box in the writes to set of password, set of password for 8 bit, can for 0~9 of digital or A~F of letters. Write and click execute, and follow the prompts to enter the same password again. Password settings are different for different protection levels of PLC, beginning of the keyword text for A,D~F,0~9 will be closed to all operations, start writing for b program will be prevented from reading and writing, rather than limit the control and change the current value, writes the letter c at the beginning of procedure of limitation, and other operations are not limited.

Reverse, Non processing and END PLC instructions

INV (Inverse) instruction in the ladder diagram with a 45 ° short slashes to represent, it will perform the calculation result be negated before the instruction, and the result is 0 it becomes 1, and the result was 1 becomes 0. In the following diagram, if X0 and X1 both ON, Y0 is OFF; otherwise, Y0 is ON. INV instructions can also be used for pulse LDP,LDF,ANDP contact instructions.

Handheld programmer type INV command, first by NOP keys, and then press the P/I key.

NOP (Non processing) for no operation, and the sequence for air operations. When you do finish clear user memory user memory contents become no operation.

END (End) to end the directive, will be forced to end the current scanning implementation process. If not END command, from the user‘s first step to the last step of the program memory; END end of Instruction in a program, perform the first step to END this program in one step, use the END command scan period can be shortened.

When in the debugger, you can insert the END directive in the wake of the program, starting from the first paragraph sub-paragraph debugging, debugging must be deleted after the program END in the middle of instructions, errorchecking program in this way is also very useful.

PLC instructions NOP

NOP instruction for no operation, mainly used for short circuit, change the circuit functions and procedures to use when debugging.
Added to the program after no operation, no effect on the results of logical operations, but when the program is changed in the future, replaced by other directives no operation, can reduce the program changes.

If no operation replace LD, LDI, ANB, and ORB directives, circuits will be more substantial changes, care must be taken.

PLC series and parallel circuit block (ANB, and ORB) command for example

ANB multiple instruction block instruction and operation. ORB multiple instruction block instruction or operation.
Example 1 press the button X0 or X1, X2 or X3 then press the switch at the same time, bright led Y1. This control requires control ladder diagrams and instructions as shown in the table as shown in Figure 1.

Example 2 press the switches X0 and X1, or when you press the switches X2 and X3, led Y1. This control requires control ladder diagrams and instructions as shown in the table shown in Figure 2.

Mitsubishi FX series PLC stepping instructions (STL/RET)

 FX series PLC basic logical instruction 20 or 27, step instructions 2, command more than 100 pieces (different series). FX2N this section, for example, described its basic logic instructions and step ladder instruction and its application.
FX series PLC stepping instructions
1. Step instructions (STL/RET)
Is designed for step instructions designed for sequential control instruction. Many control processes are available in the industrial control field controlled manner in order to achieve, using the step instruction sequence control is convenient and easy to read modify.
FX2N has two step instructions: STL (stepping contact instructions) and RET (stepping back).
STL and RET instructions only with the State s to get with step function. STL S200 for normally open contacts, called STLcontact, which in the ladder diagram symbols as it does not normally closed contact. We use for each State s record a step, STL S200 (ON), then enters the S200 represents a step (similar to the master switch), began implementation of this phase of the work of, and determine the conditions for entering the next meet. Once this signal is ON, then turn-off S200 to enter the next step, such as S201. Instruction is used to reset the STL RET instruction. After executing the RET will be back to the bus, exit the step.
2. State transition diagram
A sequence control process can be divided into several stages, also known as step or status, each State has a different action. When transitions between two neighboring States when conditions are met, it will be converted, that is performed by the previous state to the next State. We use state transition diagrams (the function diagram) describes this process of sequential control. As shown in Figure 1, each State s with a State record, x for the conditions. When X1 is ON, the system state S21 S20.

Each step in a State transition diagram contains three elements: the stepdriven content, transfer conditions and instructions change objectives. S20 driving Y0 in Figure 1, when ON is X1, then the system state S21 S20, X1 conditions for conversion, convert to S21.
3. Step instructions instructions for use
1) STLcontact is normally open contacts connected to the bus bar to the left, an STLcontact switch on, the corresponding State is active;
2) and STL contact connected to the contacts application LD or LDI instruction, only executing RET return bus on the left side;
3) STLcontact can be driven directly or through other contact drive y, m, s, t, and other components of the coil;
4) due to the PLC only implementation step corresponds to the circuit, so the use of STL instructions allow double coil output (in different step sequencer can be driven with a coil several times);
5) STLcontactdriven circuit MC and MCR instruction cannot be used in a block, but can use the CJ instructions;
6) within the interrupt routine and subroutines, you cannot use the STL instructions.

Mitsubishi FX series PLC logic end of the counter, air operations and instruction (INV/NOP/END)

FX series PLC basic logical instruction 20 or 27, step instructions 2, command more than 100 pieces (different series). FX2N this section, for example, described its basic logic instructions and step ladder instruction and its application.
FX2N total 27 basic logical instructions, containing some 20 basic logic series PLC instructions.
Logical end of the counter, air operations and instruction (INV/NOP/END)
(1) INV (against orders) after the implementation of the directive will be operated are negated. Anti-instructions of use as shown in Figure 1, if X0 broken, Y0 is ON, or Y0 is OFF. Use INV cannot like repertoire of LD, LDI, LDP, LDF and bus connections, nor as instruction sheet OR, ORI, and ORP, ORF instructions separately.

(2) the NOP (no operation) does not perform an action, but a program step. Execute the NOP does not do anything, can sometimes be shorted some NOP instructions contact or NOP instructions the instructions do not cover. When the PLC after you do the clear user memory user memory contents become no operation.
(3) END (end of instructions) show the end of the program. If the end does not write END directive PLC however long the actual user program, are performed from the user program memory, the first step to the last step if the END directive when scanning at the END, the end program execution, which can shorten the scanning cycle. While the program is debugged, several END instruction can be inserted in a program, the program is divided into several sections, in front of the identified program is correct, delete the END directive in turn, until the end of the debugging.

Mitsubishi FX series PLC stack instructions (MPS/MRD/MPP)

FX series PLC basic logical instruction 20 or 27, step instructions 2, command more than 100 pieces (different series). FX2N this section, for example, described its basic logic instructions and step ladder instruction and its application.
FX2N total 27 basic logical instructions, containing some 20 basic logic series PLC instructions.
Stack directive (MPS/MRD/MPP)
Stack instructions are the new FX series basic instructions, for multiple output circuit for programming convenience. Has 11 stores in the FX series PLC modules are specifically designed to store the intermediate results of the program, known as the stack memory.
(1) the MPS (stack instructions) the results into the stack memory in the first paragraph, while previously sent data in order to stack the next paragraph.
(2) the MRD (read stack instructions) will stack the first piece of data storage (finally push data) read out and the first paragraph of the data saved on the stack memory, stack‘s data does not move.
(3) the MPP (stack instructions) will stack the first piece of data storage (final push of data) read out and the data disappears from the stack, while other data in the stack moves up in turn.
Stack instructions use is shown in Figure 1, Figure 1a for a layer of the stack, into the stack information for unlimited use, last use the eject signal MPP instructions; figures 1B twostory stacks, stacks of it with two units.

Stack instructions instructions for use:
1) instruction is not the target component of the stack;
2) MPS and MPP malloc/free;
3) because the stack of which is only 11, so level up to 11 layers of the stack.

Mitsubishi FX series PLC master instruction (MC/MCR)

FX series PLC basic logical instruction 20 or 27, step instructions 2, command more than 100 pieces (different series). FX2N this section, for example, described its basic logic instructions and step ladder instruction and its application.
FX2N total 27 basic logical instructions, containing some 20 basic logic series PLC instructions.
Master instruction (MC/MCR)
(1) MC (master instruction) for public contacts connected in series. After the implementation of MC, left bus behind the MC contacts.
(2) MCR (master reset instructions) it is MC reset instruction instructions, the MCR instruction bus left of the restore location.
Programming often occur in such a situation, multiple coils and controlled by one or a group of contacts, if each coil of string into the same contact in the control circuit, will take up a lot of storage units, using master instruction can solve this problem. MC, MCR instruction used is shown in Figure 1, move left bus right using MC N0 M100, Y0, Y1 are under the control of X0, where N0 is the nesting level N0 use unlimited number of nonnested structures using MCR N0 restore to the original left the bus. If X0 disconnect you can skip MC, MCR instructions between down implementation.

MC, MCR instruction for use:
1) MC, MCR instruction of the target component to y and m, but not with special auxiliary relays. MC 3 program step, MCR 2 program step;
2) master contacts contacts in ladder diagram in the vertical (as in Figure 3-22 M100). Master contact is normally open contacts connected to the bus and left, is to control a set of circuit total switches. And contacts must be connected to the master contact LD or LDI instruction.
3) MC command input contact is disconnected, the accumulation in the MC and MCR timer, counter, reset/set commanddriven component state before remain unchanged. Non-totalizing timers and counters will reset with OUT of orderdriven components, such as in Figure 3-22 X0 disconnect, Y0 and Y1 becomes OFF.
4) if used in a MC extent MC instructions are called nested. Nesting levels up to grade 8, number N0 N1 N2 N3 N4 N5 N6 N7 order increases, each level corresponds to the return of MCR instruction, starting from the number of nesting levels reset.

Mitsubishi FX series PLC differential instruction (PLS/PLF)

FX series PLC basic logical instruction 20 or 27, step instructions 2, command more than 100 pieces (different series). FX2N this section, for example, described its basic logic instructions and step ladder instruction and its application.
FX2N total 27 basic logical instructions, containing some 20 basic logic series PLC instructions.
Differential instruction (PLS/PLF)
(1) PLS (rising differential instruction) on the rising edge of the input signal produces an output pulse scan cycle.
(2) the PLF (falling edge differential instruction) on the falling edge of the input signal produces an output pulse scan cycle.
Differential instruction of use as shown in Figure 1, using differential instruction signal edge is detected through the set and reset commands to control the Y0.

PLS, PLF instructions instructions for use:
1) PLS, PLF command target component as y and m;
2) when using PLS, only driven within one scan cycle of the input ON the target device ON, as shown in Figure 3-21, M0 X0 only normally open from off to ON when a scan cycle; use the PLF command only when driven by an input signal falling edge, others with the same PLS.