Designing and Installing an RS485 Serial Network

[@63Lyna]

Excellent flow of information, clarity in speaking and consistent technical information level. Very well done!

[@bempa5405]

If you use one common powersupply for all units then you dont need the 3:rd leg , but shielding is very critical in hard enviroments. Very good and easy understandable video!

[@dmitrimichlin7973]

Thanks a lot for very good presentation

[@omaralharran]

Awesome video. Thank you for taking time to make and share it :)

[@danielmarin299]

Thank you for such a great content!

[@KeithLehman-p5n]

Do you have any videos showing how to assemble the connectors with a terminating resistor?

[@anasalami9112]

well done presentation. many thanks.

[@javierlindenthal6680]

We do measure resistance when off and later voltage in action to verify and identify the different wires, dont you guys know that?

[@mamoonaleter2195]

Dear we have rs485 system in solar plant We have two wire connection and ground but the cable is 4 wire so shall i connect the two wire in paralel

[@stu6097]

How do people handle twisted wires if the two or more items in the networks have to pass through a rotating slip ring between each item? Most slip rings I see dont do any intertwining of any wires.

[@user-hi6vn1iq9p]

very useful information

[@935_moby_dick]

we used the MBS4 before and the MBSTCP to convert modbus to modbus TCP

[@solareft-gunesenerjisistem3149]

Very cool explanation

[@afathan]

i appreciated

[@manumani903]

i want to take modbus connection (rs 485) from 5 gas detectors in the field and connect to ta allen bradley mvi card. and i want to know where the daisy chain connection to be done in the field side or marshling cabinet side .

[@prosofttechnologyinc]

Hi there! Our support team will need more information to help you with this. Please contact your regional team: www.prosoft-technology.com/Services-Support/Customer-Support

[@msaner01]

Is it allowed to use a twisted pair (shielded) cable with a lower impedance of around 70 Ohms? Works a RS485-connection in general in that fact? Are there any disandvantages by cables with a lower impedance (f.e. a shorter transmission distance)?

[@prosofttechnologyinc]

Hi there! Our parent company, Belden, would best be able to help you with these questions. Feel free to contact the team at www.belden.com/support/sales-inquiry. Thank you!

[@genuinetechniques9323]

Can i connect a relay to RS485 output seen on the DVR of CCTV. it is actually meant for controlling a motorised ptz camera

[@prosofttechnologyinc]

Hi there! Our technical support team may need more information about this application; please contact your local office: www.prosoft-technology.com/Services-Support/Customer-Support

[@joellim9951]

hi there. in a 4-conductor cable for RS485, is it mandatory to connect a common ground across all RS485 devices in a master-slave daisy-chain? the use-case is for a master door access controller controlling all the slave door access controllers in a RS485 network.

[@prosofttechnologyinc]

Hi, Joel! Our tech support expert's reply: While the ground / common line is never mandatory for RS485, it is always recommended if all devices support it, as its purpose is for noise detection and mitigation. If, however, noise isn't an issue for your application, or some missed messages caused by noise is acceptable, then the common line can be seen as optional. I haven't personally run into an application where we could not get any messages through until we attached the common line due to noise, but in theory if the noise was bad enough it could effectively make the common line required, but in that scenario it might be best to try to determine the source of the noise and see if you can't, for example, re-route the wiring to avoid it.

[@JardelSG]

can I use more than one device as master in a modbus RTU network?

[@prosofttechnologyinc]

Hi Jardel! While there are some serial protocols that allow multiple masters (usually token-based ones), Modbus RTU allows only one master device on a network.

[@michaelgreen6375]

very good

[@ShravantiDasKaooor]

My question is how the rs485 addresses the no of slaves if the slave don't have built in address of its own.. how rs485 get to know which slave its talking to. Can Rs485 store the addresses of each slaves if yes then how to differentiate which slave have which no of address.

[@prosofttechnologyinc]

Hi! This shouldn't pose an issue - every Modbus slave device has a Modbus slave ID since it's a required part of the protocol. Thank you for the question!

[@mahmoudreda3959]

Thank you

[@ruturajdesai6571]

Hi there, can you please provide the circuit diagram for RS232 (DB9 connector) to RS485 converter (Screw terminal)??

[@Arthur-dc3dz]

Hi, what is the 9-pin connector for besides compatibility with the old RS232? I am building a new little network, but which might have things moving and shaking occasionally so I'd like to use sturdier and slimmer connectors that are available out there like 6 pin GX12. Is there a scenario where you would ever need more than 5 pins? Perhaps another wire for a 5v power line? That would use 6 pins tops. If I use a DB9, what could I possibly use the remaining 3 pins for?

[@prosofttechnologyinc]

Hi Arthur! We want to make sure we give you the best assistance we can on your questions - with that in mind, please call 661-716-5100 to speak with ProSoft's tech support team, or email [e-mail]. Thank you!

[@aliwaqas691]

Can we use existing 300 pair telephone cable ?

[@kirannb5354]

nice video sir...

[@Salfke]

Hi, nice learning video, i've got a question; I created my own RS485 network, with a total of 11 MAX485 chips (total length 25-30m cat5 cable, @57600 bps). At one end i've placed 680ohm between VCC and A / and a 680ohm between GND and B + a bus resistor 120ohm between A and B. when i place a 120ohm resistor at the other end of the bus, the bus signal fails . is this because of the short length? (i'm sure that no other resistors are in the bus line).

[@prosofttechnologyinc]

Hi there! RS-485 bus lengths of less than 1000 ft. usually do not require any end-of-bus termination, so take out the 120 ohm terminators at each end. If that doesn't work, call 661-716-5100 for additional Technical Support. Thank you!

[@user-wy5co6qf8u]

how can i connect between plc with rs 485 port two wire and slave with rs 422 port four wire

[@srinivass2836]

Nice

[@salmanahmet]

he says rs45 why?

[@charlpieterse3529]

This Video has nothing about designing and installing an RS485 Serial Network - It is a "What is RS485" or "What is a Serial Network". There is some good info about cables, but nothing about Design of a network

[@preetamnaik5996]

Can you tell me how you can have a multidrop connection in several rs485?

[@prosofttechnologyinc]

Hi! In order to have multiple devices connected to an RS-485 network, the wiring has to be "daisy-chained" from one device to another where the wiring goes in, and then comes back out again to the next device. The following picture is an example: www.daecontrols.com/images/Daisy%20Chain.jpg

[@masterchef6694]

what type of cable should be used for rs 485?

[@prosofttechnologyinc]

The correct cable to use in RS485 applications is Belden Part #9841. This is also the proper cable to use for Modbus Plus applications. This page talks about the various products for use with RS485: www.belden.com/products/industrialcable/eia-485.cfm. You can find the cable's spec sheet at edeskv2.belden.com/Products/index.cfm?event=printPrev&pnum=9841&ut=english.

[@baching2981]

ProSoft Technology g

[@Snickersnack329]

You have a speaker busting blast of noise in the first second of this video.