This is a placeholder topic for “Rail-Mount Serial Server RS232/485/422 to RJ45 Ethernet Module” comments.
Rail-Mount Serial Server, RS232/485/422 to RJ45 Ethernet Module, TCP/IP to serial, With POE Function…
Read moreI have purchased 2 - rs232/422/485 to Ethernet server made by waveshare. One I have connected to rs232 and have no problems. The second is for rs485. I cannot find were I can select rs485 as an option to make this work. (Waveshare shows this for other model rs485 servers) The page from your website says that it is transparent data transmission. I have gone a bit further and using a multimeter (true rms) I get no reading across A&B on powering up. I have searched online and I believe I should get a voltage reading between +/-1-5VDC, and this is so for other branded ethernet rs485 servers I have here. Your server seems to be stuck on rs232, and has difficulty registering rs485. Maybe this is a software fix? I have attempted to upgrade the firmware using the Vcom software interface, but I get error messages. Looking forward to hear if there is any support to get this server functional.
Hey @David205777, welcome to the forums!
Would you be able to share the error messages you are getting when you try and upgrade the firmware on this device?
This unit shouldn’t need you to flick a physical switch or change anything specific to work with rs485 but will likely require a software update out of the box.
@David205777 Did you manage to fix this issue or find the firmware update? I am having a similar problem with an RS422 source and MQTT configured as the output, even though it is set for transparent mode, the data is not arriving at the MQTT broker in its original ascii format.
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Hi @James224072 and welcome to the forum,
Just to confirm, have you updated the device with the software available on the Waveshare Wiki:
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Hi @Jane
The software on the wiki doesn’t include the latest firmware and doesn’t appear to have a mechanism to auto download it from anywhere. I reached out to waveshare support and they sent me a link to the firmware which I have now downloaded applied to the unit using the vircon software in the wiki. Unfortunately I dont have the end device with me to test if it made a difference but hope to check this tomorrow when I am back on site.
James
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@James224072 I did not have any success with this product. I used another waveshare product which was rs485 to ethernet only and it worked for me.
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Thanks @James224072,
Did the firmware work for you?
Hi Jane, I was able to update the firmware successfully to version v1.490 but still have the same problem with the data being sent in some sort of binary format. I’ve tried completely resetting the unit back to defaults and reconfiguring but still no change. Here’s an example of what the broker gets:
Message 17981 received on aist120 at 12:30:
b'o_[\xaaW\x9d\x9d\xa7\x9d\xa7\xa7\xa7{\x91a%\x19m\x9f\x99\x11)\x81\x8f%_\x85\x9d\x8fw\x99]\x99\x11\x11U)_\x9f\x93\xa7\x9f\xab\x93\x97\xe5\xeb\x00'
QoS: 0 - Retain: false
Thanks for responding, I am still having the same issue as well after a firmware update. My incoming data is RS422 so unfortunately I am stuck with this device (or finding another alternative).
Hi @James224072,
If its still being sent in such garbled binary format, there’s definitely something going wrong between the two protocols. What values are you using for the following:
- Baud Rate
- Data Bits
- Parity
- Stop Bits
Hi Jane,
Serial settings are 38400,8,N,1 and i have tested connecting the AIST120 directly to my PC with the same serial config and I get the output in ASCII
James
Hey @James224072,
I have seen on the FAQ @ the Waveshare Wiki that if you are receiving data with garbled characters, they recommend:
In general situations, for short-distance communication, you can remove the two 120Ω terminal matching resistors of RS422/RS485 and set the jumper cap to NC.
If you haven’t done so already, it might be worthwhile giving that a shot.
Thanks Jane, sorry I should have mentioned I’d already tried this as well, no luck I’m afraid.
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As a further follow-up, as I am only really interested in the output of the AIST120, I tried connecting it to the RS232 interface as an alternative (eg. Tx+ to Rx, and Tx- to GND) and it works fine, I get the NMEA AIS Messages sent through to the MQTT broker in their original format. So its only when data is being received through the RS422 interface that it gets encapsulated as binary. This gets me out of trouble for now but it would still be nice to know if there’s a config option I am missing or maybe its some bug.
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Hi James
Not butting here as I know little about what you are trying to do.
Are you aware (I assume so) that RS422 is only one way traffic?? I got a bit curious when you say that RS232 works. If you want 2 way traffic on a balanced line (over long distance) you need RS485.
RS232 can be used over a longer distance than usual, I have used it reliably at 75 metres. You use 2 twisted pair low capacitance overall screened cable and a bit different wiring technique.
Cheers Bob
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Silly question, on the RX422 side I assume you had TX+ to RX+, TX- to RX- and same for RX, i.e. + to + and - to -. If you crossed over anything then you could end up with inverted data, which would look wrong.
e.g.
What make me think this is I thought the RS4xx to RS232 hack was more like
i.e. RS422 TX- to RS232 RX (not the TX+) as RS232 side is inverted, so the - line is the matching one.
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Hey @James224072,
I’m glad to hear that you found a work around, but its still so strange that the RS422 is becoming garbled like that.
If you wish to pursue this further, I would recommend uploading a picture of the wiring just so we can get a couple more eyes on it and finally work this out.
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Thanks Bob,
We are only after one way traffic. To provide some additional context, the source device I am getting data from is an GME AIST120 (AIS Transceiver), it sends and receives positional messages (primarily for vessels) over VHF radio. It has an NMEA 0183 output which I believe is RS422. The Tx side is usually used to connect to a marine chart plotter which will visually display the position of vessels in the vicinity. It also supports an input on the Rx side for other NMEA devices like sensors.
My goal here is to take the AIS sentences from this device, which look something like this:
!AIVDM,2,1,3,B,55P5TL01VIaAL@7WKO@mBplU@<PDhh000000001S;AJ::4A80?4i@E53,0*3E
and send them on to an MQTT Broker, this allows me to parse these messages as they arrive, converting them to their associated metadata, for example:
{“channel”:“B”,“messageType”:21,“repeatIndicator”:1,“senderMmsi”:“995036050”,“navAid”:14,“name”:“PALM_BN1V_STBD”,“positionAccurate”:false,“longitude”:146.57385166666666,“latitude”:-18.735593333333334,“fixType”:7,“offPosition”:false,“raim”:false,“virtualAid”:true,“assignedMode”:false,“talkerId”:“AI”,“sentenceId”:“VDM”,“talkerId_text”:“Mobile AIS station”,“sentenceId_text”:“AIS VHF data-link message”,“messageType_text”:“Aid-to-Navigation Report”,“fixType_text”:“Surveyed”,“navAid_text”:“Beacon, Starboard hand”}
I use this to visualise the vessel position data on a web based monitoring dashboard using Grafana/GeoMap:
So essentially I was connecting the output (TX+ & TX-) of the AIST120 to the RX+ & RX- RS422 connections of the Serial Server and the braided ground was connected GND (I also tried the data GND but it made no difference). The serial server is configured (according to the instructions) to send that data to my MQTT broker transparently, so I should have received the AIS sentence as provided above, but instead was getting something like this:
b’o_[\xaaW\x9d\x9d\xa7\x9d\xa7\xa7\xa7{\x91a%\x19m\x9f\x99\x11)\x81\x8f%\x85\x9d\x8fw\x99]\x99\x11\x11U)\x9f\x93\xa7\x9f\xab\x93\x97\xe5\xeb\x00’
To my understanding whilst RS422 uses differential logic it is not strictly compatible with RS232, however in discussions with one of our techs he mentioned that most RS422 drivers will act like a single-ended driver if only one output is used (as in this case) and suggested as the Serial Server also has an RS232 port, that I try connect the RS422 TX+ from the AIST120 to the RS232 Rx and the RS422 TX- to the RS232 GND. As mentioned in my post to Jane, this looks to work well, so it would appear as though the RS422 interface on the Serial Server is doing some additional processing to the incoming payload.
Distance is not an issue in this use case as the Serial Server will be mounted 10-20cm from the AIST120.
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Hi Michael,
Yes thats correct, I provided some more context in my reply to Bob above. The RS232 hack was something suggested by one of the other techs here as we are only taking the transmit data from the AIST120 device and given the Serial Server also has an RS232 port. We were expecting the data to get encapsulated as it does when connected to the RS422 interface, but to our surprise it didn’t so happily moving forward with that for the time being.
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