MOXA, RS-485, ModBus RTU

[Gadjetins]

UDG-1B

- Interface type RS-485
- Exchange rate-9600 baud
- The length of the parcel is 8 bits.
- Parity - no
- Number of stop bits-1

The network address of the device and some parameters of the communication channel are configured directly in the device using the configuration SOFTWARE.

Team 04. Placement of data in registers. Measured value in Bq / m3, format
representation of numbers IEEE-754 Single.

[pitol]

What is the UNIT ID of your device? It should be configurable in the device.

[Gadjetins]

Apparently, Yes. Through the standard program from the device you can view the address of the device and change it as needed.

[RavensFan]

You seem to be confused about a lot of things.  Did you use Set Unit ID to set it to 10?

[pitol]

It seems like he did... Establishing communication seems to work since it does not return any error.

I expect that the device does not allow to read more than 10 registers.

@Gadjetins

Try to read only one register.

If register 0, size 1 does not work try register 1, size 1, etc. Be creative...

[RavensFan]

This thread has gone on so long with missing, incomplete, or contradictory information, I no longer know what the problem is.  Actually going back to message 1, the OP only stated there was an error, with no details about it.

The most recent message doesn't state whether there is still a problem.

Gadjetins,

Are you still having a problem?  If so, clearly state your current situation.  What is the problem?  What error messages are you getting? 

[Gadjetins]

Please tell me how to set stop bits in my example?

[Gadjetins]

I apologize for the bad formulation of the question! the problem is most likely in the wrong desoldering of the communication cable. now I'm looking for a description of the correct desoldering on this device. At present I try the checked cable and the device of other type, regular programs see it, but at it stop bits "2", and I cannot understand as to change them in labview.

[RavensFan]

I don't see how to do that using the Modbus library with the purple banner.  That is one thing I don't like about the Modbus libraries is that they assume a given number of stop bits.

I would recommend using the library found here.  http://www.ni.com/example/29756/en/  I believe this is one where the icons are mainly white.  But don't use the Serial MB Initialize found in this library.  This is where I first found that NI assumes a number of stop bits  (1), but a particular device may be different. (I have a device that expects 2.)  Instead, just use a VISA Serial Configure off the VISA palette to set the serial port parameters.

One other thing you could try is to configure the Serial port in MAX,  or event in Windows Device Manager to be set for 2 stop bits.  But I can't tell with that purple library if it assumes a number of stop bits and will explicitly set it to 1, or allows the setting you do in MAX or Device Manager to carry through and remain at 2.

[Gadjetins]

Found two examples on the net, but I have questions about the first picture in the red highlighted area. for me it is not clear how I can use it at myself and whether any example can help me if I alter it. The second is more or less clear, but I would like an expert opinion whether it is possible to transfer this way a command from numbers and the received answer to process? ) In the third picture I tried to remake the first image, but as a result I see an error. (port settings took for other device, the issue with the cable UDG-1B to solve it is not yet possible)