Lowpower, slewratelimited rs 485rs 422 transceivers max485 apr. Rs485 serial communication between arduino uno and arduino nano. Max253 transformer driver for isolated rs485 interface. Typically, a device designated a master requests or sends data from to slaves. In particular the max489, or any comparable full duplex transceiver. Ltc485,if you need more pinouts please download ltc485s pdf datasheet. Lms485 5v low power rs485 rs422 differential bus transceiver.
Aug 24, 2017 the oscilloscope trace was taken by snooping the rs485 communication from a commercial lighting controller. However, i dont have an ltc485 but used a max487cpa. Max485 is not slew rate limited, others on the data sheet are. Ltc485 typicalperfor ac uw ecchara terist ics receiver output low voltage vs temperature temperature c 50 0 output voltage v 0. Ds485 low power rs485rs422 multipoint transceiver farnell. Maxim, alldatasheet, datasheet, datasheet search site for electronic components and semiconductors, integrated circuits, diodes, triacs, and other semiconductors. Protecting rs485interfaces against lethal electrical transients. Rs485 allows up to 32 drivers and 32 receivers to be connected to a data bus, making it an ideal choice for multidrop. Adm485 5 v low power eia rs485 transceiver data sheet. This meter has a black housing type encapsulation that covers all the electronics, which inspires a little more confidence or certain robustness in applications, although i recommend it for indoor applications. Ltc485 transceiver datasheet pdf interface transceiver.
Ltc485 low power rs485 interface transceiver datasheet dir. The rs485 standard is ideal for multidrop applications and for longdistance interfaces. A max485 device was used as the receiver to perform the snooping operation and the blue and purple traces correspond to the signals taken from the pins marked a and b in the max485 data sheet, with reference to the 0v signal. After many hours sorting through web searches i have come up empty handed. Low power rs485 interface transceiver, ltc485 datasheet, ltc485 circuito, ltc485 data sheet. This low power transceiver module is based on the maxim max485 ic to allow serial communication over very long cable runs up 4000 feet 1200 meters. And i have some problem, i need to make a circuit with eagle for converter uart to rs485. Uart to rs485 converter hello, im more programmer than electronic. This module interfaces an arduino or similar microcomputer to rs485.
The max483, max487, max488, and max489feature reduced slew. Ltc485 5 485fi typical performance characteristics receiver tplh tphl vs temperature driver skew vs temperature supply current vs temperature temperature c 50 3. The master has a switch that operates two different functions depending on the position of it lets call them f1 and f2 i. Excessive power dissipation caused by bus contention or faults is prevented by a. The signal level is compatible with most interface ics. Max481max483max485 max487max491max1487 lowpower, slew. Description rs485 is a serial communication protocol standard based on differential signal. One arduino compatible board i use arduino nano, because i have one, but any other. Max485 ttl to rs485 interface module protosupplies. Rs485 serial communication between arduino mega and. The max481, max483, max485, max487max491, and max1487 are lowpower transceivers for rs485 and rs422 communication. Low power rs485 interface transceiver, ltc485 datasheet, ltc485 circuit, ltc485 data sheet.
Max481, max485, max490, max491, and max1487 are not limited, allowing them to transmit up to 2. Yes, you can use exactly that circuit, but be aware that it does not show the bypass capacitor on the max485 vcc pin, as asked in your next question. That means that only one transmitter can be active at a time on the bus, but all receivers can be enabled. Datasheets attached for both the ltc485 and the icpcon 7017 if anyones interested. Serial data can be transmitted in both directions half duplex at a data rate up to 2. On board max 485 chip, its a low power transceiver for rs 485 communication on board 5. Rs485 serial communication between arduino uno and arduino. The rs485 specification officially called tiaeia485a does not specifically spell out how an rs485 network.
Ill take a guess based on my experience with the max485 it will decode an open bus as an idle logic 1 condition whereas the ltc will decode it as a break logic 0. The signal level is compatible with most interface ics when at idle, the level should be high, but can be. Rs485 network failing on replacing sp485 chip with max485. All the pins of the chip are brought out, can be controlled by mcu working voltage 5v pcb dimension. Serialttl or rs232 protocol is fine if you are planning to communicate over short distances of a few meters,when yo. C driver output high voltage vs output current output voltage v 0 output current ma. Onboard max485 chip is a lowpower and slewratelimited transceiver used for. Ultralow power rs485 with low emi, shutdown and high input impedance. I have a pic16f1708 as master and another one as slave. Rs232 rx pin 5 this is the rs232 serial data receive input. Liner, alldatasheet, datasheet, datasheet search site for electronic components and semiconductors, integrated circuits, diodes, triacs, and other semiconductors.
General description the max481, max483, max485, max487max491, and max1487 are lowpower transceivers for rs485 and rs422 communication. Low power rs485 interface transceiver online from elcodis, view and download ltc485 pdf datasheet, linear technology corporation specifications. So8 pinout is the same as popular ltc485 and lt1785. Hi folks,here we are going to interface a msp430 launchpad with a rs485 transceiver chip like max485 and communicate with an x86 pc. The terminations reduce voltage reflections that can cause the receiver to misread logic. L, lt, ltc, ltm, linear technology and the linear logo are registered trademarks of linear. Read and interpretate rs485 signal with max 485 and arduino. All three new devices are pin compatible with the industry standard ltc485 pinout, and feature linear. In half duplex mode it has a data transfer rate of 2.
Well, this is my problem, theres a signal coming from a central server which is rtu rs485 protocol im 100% sure about that, id like to traduce that signal into ascii characters after pass through a max 485 and the arduino and present them in the serial monitor of the computer. I ordered several of each chip, including the max485 which seems to just be a higher voltage. Rs232 rx pin 5 this is the elm325s serial data receive input. Multisim experts, i have been on the hunt for an rs485 transceiver spice model.
Max1487 are lowpower transceivers for rs485 and rs. Rs485 module for arduino max485 click photo above for details, then hover over upper right for more photos. The ltc485 is a low power differential busline transceiver designed for multipoint data transmission standard rs485 applications with extended common mode range 12v to 7v. This meter has rs485 and modbus rtu slave protocol, which facilitates communication since modbus rtu in rs485 is an industrial standard. After about 1 minute it gets warmer touchable but warm, and soon it stops transmitting or at least. Max488 allows full duplex operation 485 is halfduplex only. Information furnished by analog devices is believed to be accurate and reliable. Ltc485 is fully specified over the commercial and extended industrial temperature range. The attached schematic shows a max485, but that chip is compatible with the lt1785.
Ltc485in8 ltc485is8 ltc485m ltc485mj8 datasheet pdf downlaod from. Lowpower, slewratelimited rs485rs422 transceivers max485. Page 3 of 35 rs485 guide 0702 rev 6 introducing the modbus protocol this document is intended to provide an introduction to the modbus implementation of integra and spr. This application note is intended to provide basic guidelines for wiring an rs485 network. Do i have to use a max485 chip in front of an atxmega microcontroller. Pin and functional compatible with max485 and ltc485.
For pricing, delivery, and ordering information, please contact maximdallas direct. Its bicmos design allows low power operation without sacrificing performance. Ltc2862the next step towards to the perfect rs485 transceiver. The max483, max487, max488, and max489 feature reduced slewrate drivers that minimize emi and. These transceivers draw between 120a and 500a of supply current when unloaded or fully loaded with disabled drivers. Ltc485 linear technology corporation, ltc485 datasheet. The max483, max487, max488, and max489 feature reduced slewrate drivers that minimize emi and reduce reflections caused by improperly terminated cables. I was able to locate ibis models for the transceiver, but converting i. Did you try linear technology ltc485 maxim max485 directly replacement equivalent. Rs485 serial communication between arduino mega and arduino.
Sp485 max485 are rs485 transceivers requiring 5v power supply. Ltc485 low power rs485 interface transceiver description. Max487cpasn75176bp rs485 ic gets too warm in dmx splitter. Is there any difference between the max485 chip versions. The standard is defined by industry telecommunications bodies and may be referred to most commonly as rs485, but references to eia485 or tia485 may also be seen. Rs485 communication using max485 and msp430 launchpad. Additionally, the max481, max483, and max487 have a lowcurrent shutdown mode in which they consume only 0. In a balanced differential system the voltage produced by the driver appears across a pair of signal lines that transmit only one signal. Max485 datasheetpdf 1 page maxim integrated products. Aug 22, 2017 hi, im a newbie with usart, i wonder if someone can point me in the right direction for the work i want to do. Ltc485, maxims max485, and national semiconductors ds3695. Ill take a guess based on my experience with the max485 it will decode an open bus as an idle logic 1 condition whereas the ltc will decode it. The max485 is halfduplex differential transceiver that meets the requirements of rs485 and rs422.
I have one question, its not so important, i just want to know. Datasheet says that the slew limiting limits data rate operation to 250kbaud. Parameter min typ max unit test conditionscomments driver differential output voltage, v od 5. Feb 18, 2019 for using rs485 in arduino, a module called 5v max485 ttl to rs485 which is based on maxim max485 ic is needed as it allows serial communication over long distance of 1200 meters and it is bidirectional. Rs485 is used for serial communications over longer distances than direct rs232 or ttl, and supports multiple units on the same bus multidrop. Ltc485 low power rs485 interface transceiver analog devices. The cmos design offers significant power savings over its bipolar counterpart without sacrificing ruggedness against overload or. Ltc485 datasheet, ltc485 pdf, ltc485 data sheet, ltc485 manual, ltc485 pdf, ltc485, datenblatt, electronics ltc485, alldatasheet, free, datasheet, datasheets, data. The ltc485 is fully specified over the commercial and extended industrial temperature range. Driver skew vs temperature output voltage v 0 output current ma 40 50 60 4. Ltc485 datasheet,ltc485 pinout pin out,ltc485 application circuits can be. Ltc485 low power rs485 interface transceiver from old datasheet system. Uart serial to rs485 module max485, rs485 electrodragon.
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