A control signal basic classification:
1 switch (numeral) input
A) does the electronic contact --------- to operate the button (switch), the travelling schedule and the limit switch, the relay, the contact device auxiliary contact and so on. Because the PLC input end leads 通电�?is 5-7mA, is stable for the guarantee signal, must cause the input end leads passes when the electric current to maintain at 3.5 and 4.5 mA. If because contacts not good or the wire excessively is long then easily is disturbed. Moreover larger capacity contact device auxiliary contact when 小电�?should consider its contact is reliable.
B) approaches the switch, the photoelectricity switch, the collecting electrode leading the way encoder and so on --------- this kind of part mostly sets to the scene, has in the certain distance with PLC, has the possibility which disturbs, should select the switch performance good product as far as possible. Generally easily is disturbed in the level gap/pulse width compared to the big situation in.

C) the differential motion encoder --------- this kind of form sensor comparatively suits in the long distance, the high velocity situation, is disturbed the opportunity to have to be less than former. But collecting electrode leading the way can because the wire excessively long weaken power output.

2 switches (numeral) output:
A) the relay ----------- uses in to actuate the contact device, the solenoid valve, the flare, the electronic circuit and other equipment. The load power source is below below DC30V and AC240V. If the AC load, for a convenience row of line, this kind of control signal may place in once in the usual situation with the power line. Under the DC load and equipment of nature the actuation regards the truth according to its voltage rank to decide.
B) the transistor outputs (DC5-30V) I actuates the relay, the indicating lamp, the electronic circuit and other equipment, when the low voltage load must consider the disturbance factor. II by level or pulse form actuation frequency changer, positioning device, electronic circuit and so on. The suggestion and the power line maintain in the suitable distance, at least 30cm. When system design considered is far away as far as possible possibly mutually has the influence equipment.
C) the matters needing attention -----------PLC output meets the external load (contact device, solenoid valve) the equisignal part, should affix according to the alternating and direct nature anti- accommodates the absorbing circuit or the after flow diode. Although the Mitsubishi PLC promotion until now by no means because of neglects this work to cause the disturbance, but can cause its internal the output part to reduce the life exterior, and is very easy to affect the electronic installation, the effect is obvious.

3 simulations inputs:
Turn on PLC by the voltage or the electric current form, generally from each kind of examination or the control device (sensor, instrument measuring appliance and so on) center outputs, like they because the line excessively is long, the use not when or question and so on itself quality then easily is disturbed then imitates obstructs the system the operation. When especially small signal, suggested uses the electricity flow pattern input.

4 simulations outputs:
By the voltage or the electric current form from the PLC output to the correlation equipment, are same, pays attention to when the small signal the reliability with the simulation input, like in long distance when disturbance and attenuation and so on.

5 communication lines:
A) optical cable ------------ because is separated from the level transmission the way, therefore can carry on the high efficiency, the low loss information transmission. But not electronmagetic interference influence.
B) the coaxial cable and the twisted pair line ----------- are the electrical connection, has the level transmission the characteristic. In the coaxial cable because the medium good, the structure purifies transmits is apart from far, the speed high, the chain reception depot number many, little receives disturbs, but the construction cost is high. The twisted pair line is lower than former in this aspect performance, but the price economy, the platoon line is convenient, may voluntarily manufacture. Is huge, under the spatial limited situation in the system suits (must meet terminal resistance). When arrangement transmission line cable should achieve with every effort with the power line, the pilot wire separates but alone walks, guaranteed the entire system the communication is unimpeded, is not disturbed. At present Shang Shao discovered the Mitsubishi product because of disturbs but because the communication abnormal phenomenon.

Because user forms a complete set when the equipment selects the Mitsubishi product only is of a part systems, voluntarily has disposed the certain quantity peripheral equipment, like the low pressure electric appliance, the electrical machinery, the solenoid valve, the sensor, the instrument measuring appliance, the electronic circuit, the computer, each kind of network and other labor control the product. Some products or the network all have the industry standard by no means or has not experienced the test, after the system integration mutually possibly has the influence. Therefore in the system design, the part selects, the equipment takes place, the installment, meets row of aspect and so on line, debugging, maintenance all has the reasonable or not question, will have the congenital condition limit also to have the day after tomorrow human factor, or just moved when will be normal later causes the environmental variation along with many reasons to cause exceptionally.

The electric appliance forms a complete set when for the reduced disturbance opportunity, should according to the related profession gauge custom make related preparatory work, cease the hidden danger. In view of the fact that the system design, the equipment take place and so on the matters concerned acts according to respective factor and so on production situation, operation requirements, fund condition by the user measures decides, inconveniently at will changes, here only makes a suggestion from the electrical aspect, including:
1 equipment takes place ---------- in the overall system big principle already in the situation which determined (including electrical cabinet in part), the reference principle, achieves the arrangement to be reasonable with every effort, is advantageous for the reduced invalid platoon line way to reduce the harmful factor.
2 row of lines ------------ if the condition limits the inconvenient detailed classification also to be supposed approximately to divide into strongly, the weak electricity, and guaranteed as far as possible the line cable reduces the parallel opportunity to reduce between the wire the mutual inductance. When, the weak electrical signal line is longer may select the twisted pair line method according to the need to reduce the distributed capacity and the mutual inductance.

3 even if is unable the interference elimination on the hardware, sometimes also may use in the partial situations to supplement the corresponding procedure the method to improve.

At present reflected according to the user, generally when used high-speed counting, the temperature control, the frequency changer, the servo (step entered) installs and so on the product has been easy to appear the disturbance phenomenon.
1 high-speed counting module AISD62:
The encoder and the module are distanced 30m, appears counts when has does not permit (pulse to lose) the phenomenon. Installs the wiring request to be supposed to coincide the encoder and the power source should alone connect, but cannot through the module power line way, after the correction the situation improvement.

2 thermo-elements temperatures module FX2N-4AD-TC:
The temperature value often jumps does not decide, the scope is 3-5 �? interfered with the unit work, in the procedure is connected BFM to the average sampling points to carry on has repeatedly adjusted, does not have the effect. Latter will compensate the wire the shield end to change will meet to 0V of module electric power supply, the situation distinct improvement. Its undulation scope is 0.1-0.3 �? In certain above situations if took the measure still not to have affects, might use the thermo-element + to change the delivering + ordinary A/D module the way, because changes delivering itself to form as soon as isolates the link, therefore can solve the value perturbation problem in an greater degree.

3 localizations modules FX1S (1N), FX2N-1PG, FX2N-10 (20) GM:
The related localization module and the servo unit antijamming measure may refer the product user's manual, here simply explains and the step of 进电 machine driver connected situation. Many steps of 进电 machine drivers and the import product comparison have the difference, the common phenomenon causes the electrical machinery for because the disturbance pulse to fall out of step creates the position error to be big, besides adopts with the servo unit similar method, a simpler procedure may install the filter to perform to improve. Because the pulse actuation class equipment operating frequency scope is wider, certainly did not know its input () the impedance, calculates with difficulty, therefore not easily installs a self-made filter kind of part, does not select when not only can absorb the normal high frequency pulse, moreover reduces the system the response level, is subject to duty to decide to the special details.

4 frequency changers FR-E500:
User has installed many A500 and the E500 series frequency changer when the electrically controlled cabinet, the movement has many E500 frequency changer to appear operates on the kneading board the frequency demonstration is 0, also the RUN instruction extinguishes, but moves as usual. Presses any to restore the demonstration. In the observation discovered all frequency changers ground terminal is connected to the electric appliance cabinet box body, but the box body earths by no means. The earth is a stricter work, must do thoroughly, if unconditionally may temporarily not earth, makes one half but the shed one half, then is easy to cause the disturbance. The equipment transports after the scene official earth the breakdown elimination.
5 frequency changers FR-A500:
The frequency changer moves when forms the disturbance to the user control measuring appliance, after downloads the electrical machinery to cause the frequency changer lost motion, the system to be normal, initially the judgement should be the result of for the output line noise, selects the FR-BLF line noise filter to meet to frequency changer U, V, between the W end and the electrical machinery. The degree of disturbance obviously reduces. If the line noise comes by no means from to the load, but is the source to the electrical network input, then may meet the filter to 进线leans R, S, the T end.
6 in certain situations because is unable the complete interference elimination, may increase the procedure in software, its principle for reduces receives disturbs the data the sensitivity, through fixed time the average calculating operation, causes it relatively slowly, is not easy to undulate. Certainly, it only suits in the real-time request not high situation.

Above involves the product function and the engineering data only take Mitsubishi's product as the reference, the related content also only was myself formerly is working some experiences, these phenomena productions surmounted some brand product by far the scope. In view of the fact that the disturbance phenomenon complexity and not reason and so on determinism and scene experience, some understanding is not certainly comprehensive. Looks the colleague which has the correlation experience to perform to supplement, to point out mistakes, well the maintenance and the enhancement is engaged in prestige of the product.

Hangzhou and the China electrical engineering company Mitsubishi labor controls level of proxies, the Mitsubishi labor controls the special service service center
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