Рук_п_АК-8 (1031889), страница 23
Текст из файла (страница 23)
When someone turns on another hot water hydrantnear the Heater, you’ll be impressed with the cold water!The bottom diagram of above figure just shows that those devices willinfluence each other with swiftly load change. For example, normallywe turn on all the four hydrants for testinF.
When you close thehydrant 3 and hydrant 4, the other two hydrants will get a more flow. Inother words, the hydrant can not keep a constant flow rate.F-8ADAM-5000Appendix FSingle Point GroundingADAM4013ADAM4014ADAM4017ADAM4021+16V+18V+20V+228+22V+22V+22V+228ADAM4013ADAM4014ADAM4017+24VPowerSupplyADAM4021+24VPowerSupplyMore cable, but more stable system.Figure F-8: Single point groundinF. (2)Above diagram shows you that single point grounding system will bea more stable system. Actually, when you use the thin cable poweringthose devices, the end device will get lower power. The thin cable willconsume the energy.F.2Shielding2.1 Cable ShieldFigure F-9: Single isolated cableADAM-5000F-9Grounding Reference• Single isolated cableAbove diagram shows you the structure of the isolated cable. You cansee the isolated layer spiraling Aluminum foil to cover those wires.This spiraled structure makes an isolated layer for isolating the cablesfrom the external noise.Figure F-10: Double isolated cable• Double isolated cableYou can see the double isolated cable structure as figure 10.
The firstisolated layer spiraling Aluminum foil covers those wires. The secondisolated layer spiraling and crossing several nude conductors coverthe first layer shielding and those wires. This spiraled structure makesan isolated layer for isolating those external noise.F-10ADAM-5000Appendix FBesides, following tips just for your reference.• The shield of cable can’t be used for signal ground.The shield is just designed for adhering noise, so the environmentnoise will couple and interfere your system when you use the shield assignal ground.• The density of shield is the higher the better, especially for communication network.• Use double isolated cable for communication network / AI / AO.• Both sides of shields should be connected to their frame while insidethe device. (for EMI consideration)• Don’t strip off too long of plastic cover for solderinF.2.2 System ShieldingRS-232ADAMADAMADAMADAM4520401340174021Terminal Block+24V* Never stripping too long of the plastic cable cover.* Cascade those shields together by Soldering.PowerSupplyConnect the shield to Frame-Ground of DC Power Supply.Figure F-11: System ShieldingADAM-5000F-11Grounding Reference• Never stripping too long of the plastic cable cover.
Otherwise, thisimproper status will destroy the characteristic of the ShieldedTwisted-Pair cable. Besides, those nude wires are easy to adhere thenoise.• Cascade those shields together by “Soldering”. Please refer tofollowing page for further detail explanation.• Connect the shield to Frame-Ground of DC power supply to forcethose adhered noise flow to the ‘frame ground’ of the DC powersupply.
(The ‘frame ground’ of the DC power supply should beconnected to the system ground)Figure F-12: The characteristic of the cable• The characteristic of the cableDon’t strip off too long of plastic cover for solderinF. Otherwise willinfluence the characteristic of the Shielded-Twisted-Pair cable, and willmake an easy way to adhere noise.F-12ADAM-5000Appendix FFigure F-13: System Shielding (1)• Shield connection (1)When you want to visit somewhere, you must like to find out aneasiest way to achieve your goal, aren’t you? So as electronic circuit,all signals use the easiest way. If we connected those two cables justwith few wires, it is a difficult way for signal.
So the noise will try tofind out another path for easier way for flow.Figure F-14:System Shielding (2)ADAM-5000F-13Grounding Reference• Shield connection (2)Above diagram shows you that the fill soldering just makes a easierway for the signal.F.3Noise Reduction Techniques• Enclose noise sources in shield enclosures.• Place sensitive equipment in shielded enclosure and away fromcomputer equipment.• Use separate grounds between noise sources and signals.• Keep ground/signal leads as short as possible.• Use Twisted and Shielded signal leads.• Ground shields on one end ONLY while the reference grounds arenot the same.• It’s almost communication problem while system unstable.• Add another Grounding Bar if necessary.• The diameter of power apply cable must be over 2.0 mm2.• Independent grounding is needed for A/I, A/O, and communicationnetwork while using the jumper box.• Use noise reduction filters if necessary.
(TVS, etc)• You can also refer to FIPS 94 Standard. FIPS 94 recommends that thecomputer system should be placed closer to its power source toeliminate load-induced common mode noise.F-14ADAM-5000Appendix FFigure F-15: Noise Reduction TechniquesF.4Check Point List• Follow the single point grounding rule?• Normal mode and common mode voltage?• Separate the DC and AC ground?• Reject the noise factor?• The shield is connected suitable?• The diameter of wire thick enough?• How about the soldering of connection?• The terminal screw tightly?ADAM-5000F-15Grounding ReferenceF-16ADAM-5000.
![](https://s.studizba.com/z.php?f=/templates/si/i/noavatar.png&w=100&h=100&t=1"){kind=avatar}
