Tag Archives: PLC ladder diagram

Mitsubishi PLC ladder diagram cannot be converted

The solution is
In the tool-option, remove the √ in front of the step ladder stt in the contact format, and then change the program. After the change, convert the save and then hit the √.

What time relay is used for Mitsubishi PLC power-off delay

Mitsubishi does not have a power-off delay to close the relay. Only the power-on delay closes the relay, but it can be implemented by a program.

as the picture shows,
When X0 is ON,
M0 reset,
M0 is disconnected in front,
T0 does not count,
When X0 becomes OFF,
M0 is set and T0 starts counting.
Time is up,
When the contact T0 is output, the function of closing the power-off delay is reached.

How to use the gx developer timer to time one hour

Use two timer relays, first make a half-hour timer, 18000X0.1=1800 seconds, this timer will trigger an M point again, use this M point to trigger another half-hour timer again.

Mitsubishi plc programming Ladder diagram: motor is rotating for 10 seconds, inversion for 8 seconds, cycle

Ladder diagram:

Press X0, M0 is energized and self-locked.
At the same time, KT1 is turned on and Y0 is output. At this time, the motor is rotating 10S.

When the 10S time is up, T1 disconnects YO, and M1 is powered on and locked.

At the same time Y1 output, the motor is reversed.

KT28 seconds to the time, M0 reset, at this time a working cycle is over, automatically enter the next cycle.

The most simple and safest delta voltage starting circuit diagram

circuit diagram

Siemens PLC S7 300/400 master relays orders

Main control relay (Master Control Relay), abbreviated as MCR. MCR Master relay command is used to control whether normal execution of the instruction in the region, equivalent to a connect and disconnect the flow of the main switch. MCR instruction is not much used, S7-200 is no MCR instruction.

MCRA to activate the master relay instructions, MCRD to deactivate the master relays orders.

Open the master relays orders MCR< in the MCR before you save the results of logical operations on the stack RLO (MCR), close the master relays orders MCR> MCR saved out of the stack in the RLO. MCR< and MCR> used to indicate controlled temporary power cord formation and termination.

MCR instructions can be nested, MCR the MCR can be another zone. MCR stack is a LIFO stack, allowing the maximum nesting depth of 8 levels.

MCRI0.2 control, I0.2 and MCR MCR in the stack level of the same State. MCR bit is 1 when will perform Q4.0 coil MCR control area and MOVE instructions. MCR bit is 0 when Q4.0 is 0.

Siemens plc S7 300/400 ladder logic blocks in calling instructions

CALL in the ladder diagram coil can call functions (FC) or system functions (SFC), the call cannot be passed parameters. Calls can be unconditional, CALL directly connected to the vertical line on the left side of the coil, equivalent to UC in the statement table orders; can also be conditional, condition provided by the control CALL contact circuits of coils, equivalent to CC in the statement table instructions.

Logical block is called if you need to pass parameters, you can use the command to invoke the function block in the box. FB 3-70 box in Figure 10 is the function that is being invoked, DB3 is called FB 10 o’clock block of background data.

Conditions for return instructions (Return,RET) appears as a coil, left logic for conditional block conditions provided by the contact circuit to control it, RET coil cannot be connected directly on the left of the vertical power cord. If you call it is the unconditional return, at the end of the block does not require the use of RET instruction.

FX2N series PLC position control module

In machine operation, speed and accuracy are often contradictory, in order to improve machine efficiency and increase speed, parking control there is a problem. So it is necessary to control. As a simple example, motor driven mechanical home by starting location, such as at top speed to return, due to the high speed stop inertia, the deviation in the home has to be large, slow down to ensure the accuracy of positioning.

Position control systems, often adopt servo motor and stepping motor driven device. Openloop control and closedloop control can be used. For stepper motors, we can adjust the send speed to change the machine‘s working speed of the pulse. With the FX series PLC, navigate through the pulse output of the unit or module, you can achieve the position of one or more points. FX2N series are described belowpulse output module and the control module.

(1) pulse output module FX2N-1PG. FX2N-1PG pulse generator unit can complete a separate axis of orientation, this is achieved through servo or stepper motor drive amplifier provides a specified number of pulses to achieve. FX2N-1PG is only used for FX2N series, with TO/FROM instruction set various parameters, and speed read out position value. The modules take up to 8 I/O point. Output up to 100kHz the pulse train.

(2) the controller FX2N-10GM. FX2N-10GM for pulse output unit, whether it is a singleaxis positioning unit, not only can handle single-speed, and interrupts location, and can handle complicated control, multi-speed operation. FX2N-10GM can have up to 8 connections on the FX2N series PLC. Maximum output is 200kHz.

(3) positioning controller FX2N-20GM. A FX2N-20GM controlled twoaxis, performs linear interpolation, circular interpolation or independent twoaxis positioning control. Maximum output pulse trains of up to 200kHz (interpolation period, a maximum of 100kHz).

(4) the programmable cam switch FX2N-1RM-E-SET. In the mechanical drive control, often to diagonal position detection, different at different position in terms of conduction, shutdown signal. Used mechanical cam switches, mechanical cam switches and high precision, but easy to wear. FX2N-1RM-E-SET programmable cam switches can be used to replace mechanical cam switches for high precision angle position detection. Complementary angle sensor cable length of up to 100m. Application and other programmable cam switches, brushless resolver high accuracy angle setting and monitoring its internal EEP-ROM, no batteries, can hold up to 8 different programs. FX2N-1RM-E-SET on the FX2N, can also be used independently. FX2N maximum 3. It takes 8 I/O point.

FX2N Series PLC data communication module

PLC communication module is used to complete with other PLC intelligent control, other communication between devices or computers. Following brief introduction to FX serial communication function expansion board, adapter and communication modules.

(1) communication expansion board FX2N-232-BD. FX2N-232-BD is to connect standard PLC and other RS-232C transport device interface board, such as personal computers, bar code reader, or printer. The panels can be installed inside the FX2N extension. The maximum transmission distance is 15m, the maximum baud rate for 19200bit/s. PLC using special software for the extension plate can be running monitoring, can also be transmitted from the PC to the PLC program.

(2) communication interface module FX2N-2321F. FX2N-2321F on connect FX2N series PLC can realize RS-232C with the other fullduplex serial communications interface devices, such as personal computers, printers, bar-code reading device and so on. FX2N series FX2N-2321F modules can connect up to 8 blocks. The module using FROM/TO command to send and receive data. Maximum transmission distance is 15m, the maximum baud rate for 19200bit/s. The modules take up to 8 I/O point. Data length and serial communication baud rate can be set by a special data register.

(3) communication expansion board FX2N-485-BD. FX2N-485-BD for RS-485 communication. It can be applied to no agreement on data transfer, 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. Transmitting maximum transmission distance is 50m, the maximum baud rate for 19200bit/s. Each of the FX2N series PLC expansion boards can be fitted with a FX2N-485-BD communication. In addition to using this communication expansion boards and computer communications, 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 communications, can be connected on 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.

Above on the FXseries only gives a brief introduction to the communication module, specific application again in detail in later chapters.

Siemens S7-200 PLC programming examples – Belt conveyor control

To look many PLC Ladder Diagram is better for learn plc programming. you can learn the plc programming Thoughts and ideas. here is siemens s7200 plc rpgramming examples.
(1) control requirements
Motors M1, M2, M3 three drive belt conveyor.Press the start button SB1, start the order of M1, M2, M3, the interval of 3s.Press the stop button SB2, the order of the parking for M3, M2, M1, the interval of time is 3s. Three motors M1, M2, M3 respectively through the contactor KM1, KM2, KM3 connected three-phase AC power supply, with PLC control of the coil of the contactor.

(2)Address allocation table for programming elements
 Programming element
I/O terminals
(program address)
Circuit devices
(PT timer value)
 input relay
start button
Stop button
 output relay
M1 Contactor
M2 Contactor
M3 Contactor
Start first period of time
Start second period of time
Parking first period of time
Parking second period of time
Auxiliary relay
Parking holding first
period of time
Parking holding second period

(3)Ladder Diagram

PLC ladder programming