Rs485 air temperature humidity and pressure sensor

Products & Technology SenseCAP
1

Recently we have received rs485 air temperature humidity and pressure sensors.

I am not able to get it to work.

In the manual it says to use the Qmodbus program, i get an error:

Protocol error: slave threw exeception: unkown error or function not implemented.

If i connect an other type of sensor everything works ok.
This type of sensor does not seem to work.

Is it a production failure / hardware problem or is there some thing i have to set before the sensor works ?

Regards,
Peter

2

Hi there,
So this is a very good sensor, but I feel your pain with the comms.
RS_485 is one of the most versatile interfaces , support P2P, Master/Slave, Multi-Drop. and more.
Takes a bit to get it going , but most robust of all of them.
have you loaded the App?

What code have you tried, and how do you have it connected. Any pictures?
of post up the code you are trying.
HTH
GL :slight_smile: PJ
:v:

3

PJ,

Thanks for your quick response.

I have downloaded the app.
I do not think there is any problem with the rs485 communication, i have an other type of rs485 sensor that runs without any problems with the app.
The sensor does not seem to response.

My own test app can get the sensor to response only once after powerup and only the second response i send is acknowledged. It looks like the response is ok.

The qmodbus app does not give any response, it only sends 1 request.

Can you tell me did you use this type of sensor, it seems quite new ?

I can give you print screen later this week if you are interested and also information about the other sensor i am using that is working ok.

I have the feeling the sensor goes into sleep mode and is unable to respond to commands.

I have limited time now, let me know your thoughts and what information you want to have.

Regards,
Peter

4

Hi there,
I have seen it, and I believe it changes baud rate after the initial power up or something wacky like that,
May be bad but they either work or not, not really sort of, so I get it strange when others work same situ.
You have a picture of the actual unit, maybe the label. I have used this and a Plethora of Sensors Like it in the semiconductor FAB, ULP testing, A cornucopia of every kind that exist to day and even One based on a Frozen mirror lazer LED “space ship” type tech, as a moisture analyzer LDL down to PPT. Sub micron Laser particle counters and Liquid Oxygen analyzers RGA hydrocarbon analyser for Ti and stacks like this. Scada systems

PTS_FAS_2
PTS_FAS_2309Ă—400 12.8 KB

PTS_3
PTS_3384Ă—400 14.9 KB

PTS_FAS
PTS_FAS342Ă—400 19.2 KB

later made them carts and mobile with onboard Nitrogen Purge manifolds.
and more recently, did this SSG for a Medical device manufacture.
So yea I’ve
ssgfillmonitor
ssgfillmonitor227Ă—403 27.8 KB

built a few things, programmed allot of things and Love this Stuff.
HTH
GL :slight_smile: PJ
:v:

5

Hi,

I have worked on the problem. I think the way the sensor is working is not properly documented !

I can get the sensor only to work in the following order:

  1. Put power on the sensor
  2. Within 15-20 seconds send a read request 2 times.
  3. The sensor responses

After this the sensor is not responding anymore.
Could anyone tell me if this is the way it is supposed to work ?

printscreen_readout_sensor
printscreen_readout_sensor1281Ă—642 29.3 KB

regards,
Peter

6

Hi there,
Peter. Yea that seems very wrong, If you leave it warm up and powered on but do not try to communicate with it, for say 5 minutes. Does it respond? if NO, I would fire off an e-mail to seeed tech support, That thing must be bad. Could it be changing the “baud rate” to something else after the required warm-up time?? do you get any gibberish type data after that?
my .02
GL :slight_smile: PJ

7

PJ,

I have tried as you suggested to power the sensor for a long time (even 15 minutes).
Still the same result no response. I do not get any gibberish response either, i have tried with different baud rates to see if i can get it to work.

Do you know how i can reach to seeed tech ? i understand the forum is the only way to ask support.

Regards,
Peter

8

Hi there,
Yes , just send an email on here(as message) click on the Support techs profile, Seedserphina, or Citric will get it to the right folks.
HTH
GL :slight_smile: PJ
:v:

9

PJ,

You write clear, but i fail to find an option to send a message.
I have found the profile of seeed Seraphina but i fail to find where i send this person a message/mail.

Could you explain where to send a message ?

Regards,
Peter

10

Sure, it’s not real intuitive , took me a minute the first time too.
LOL :v:

send a message.
send a message.2736Ă—1432 200 KB

HTH
GL :slight_smile: PJ
click their profile too.

send a message2.
send a message2.2025Ă—1017 104 KB

11

PJ,

I have managed to send a message.
I hope i get a response.
After “message” i took new an there was a link where i could fill in a message form.
I had to put in the order number so i hope it will be picked up
Thanks for your help.
Regards,
Peter

1 Like
12

I have several pieces of this sensor. They have default slave address of 1 and I need to change the slave address so that they can be addressed on the same bus.
I use this mbpoll command to change address of one device to 2 and it does not respond anymore.
mbpoll -m rtu -a 1 -r 513 -t 4:int -1 -d 8 -b 9600 -s 1 -P none /dev/ttyUSB0 2
Is anyone successful with changing slave address? How do you do it?
Thanks

13

Hi,
My problem with the sensor had nothing to do with the sensor.
The rs485 module i used did not work in combination with the sensor.
After buying a new model all worked out of the box.

To change and test the sensor i use windows and the Qmodbus program.

I have changed the adress without any problems !

1 Like
14

Thank you. I use Qmobus and I can change slave address fine now.
Another question: can I dip the tip of this device in water to measure water temperature? I need to do this for about 48-72hrs and it’s o.k. if the device is damaged after that.
Anybody try this before? The device is for outdoor use, and I think it’s o.k. to dip in water, right?

15

Hi,
A strange question: can I dip the tip of the device in water to read water temperature? I need to do this for about 48-72 hrs and it’s o.k. if the device stops working after that. I just need to collect data for 48hrs and that’s it.

16

Hi there So based on the spec PDF posted above the unit has An IP56 rating means a device is protected against a limited amount of dust ingress and is protected from high-pressure water jets from any direction. This makes it suitable for outdoor use or industrial settings where it may be exposed to both dust and powerful water sprays, but it is not completely waterproof

Practical implications

  • Not submersible: Devices with an IP56 rating are not designed to be submerged in water.
  • Good for outdoor use: This rating is excellent for equipment that will be exposed to elements like rain or cleaning with hoses.
  • Industry-specific applications: This rating is common for industrial control panels, equipment in workshops, and public electrical installations where dust and powerful water are a concern.

C’mon Man . YOLO :stuck_out_tongue_winking_eye::crossed_fingers:
TRY IT…:grinning:

HTH
GL :grin: PJ :v:

report back please… If you go all OceanGate Titan on it…

17

Hi,

I agree with Glasso, you can allways try and see what happens.

But if you want to collect data these might be false !

An other option is to buy a modbus temperature sensor that can work in water.

Regards,
Peter