Support Forums
modbus timeout

Hello,

i want to use a DT85 to query a Modbus RTU Sensor(Meier-NT Soitemperature Probe).

From my point of view i did all the necessary configuration but somehow i dont get any response from it.

Here is my Setup:

Hardware configuration:

A-Wire: TxZ
B-Wire: RTSy
Power: 12V Source
Ground: Common Ground with DGND

Software configuration:

[SERSEN_PORT]
  *BPS = 19200
   DATA_BITS = 8
   STOP_BITS = 1
  *PARITY = NONE
   FLOW = NONE
  *MODE = RS485
  *FUNCTION = MODBUS_MASTER

I guessed the flowcontroll because it is not clear from the documentation of the sensor

Reference from Sensor documentation(german):

647898b8c927b

I know that the sensor is working since when i connect it the same way to another datalogger(Meier-NT ADL-MX) it works.

Here is the output when trying to query the sensor with P56=4:

DT85> 1modbus(ad2,R3:30003)
1modbus(ad2,R3:30003)
Modbus TX >SS: 02 04753200018a3a (8)
Modbus timeout
dataTaker 85 E124 - Modbus transaction failed
1MODBUS NotYetSet

Is there any other way to debug or am i doing something wrong?

Hello, i want to use a DT85 to query a Modbus RTU Sensor(Meier-NT Soitemperature Probe). From my point of view i did all the necessary configuration but somehow i dont get any response from it. Here is my Setup: Hardware configuration: ``` A-Wire: TxZ B-Wire: RTSy Power: 12V Source Ground: Common Ground with DGND ``` Software configuration: ``` [SERSEN_PORT] *BPS = 19200 DATA_BITS = 8 STOP_BITS = 1 *PARITY = NONE FLOW = NONE *MODE = RS485 *FUNCTION = MODBUS_MASTER ``` I guessed the flowcontroll because it is not clear from the documentation of the sensor Reference from Sensor documentation(german): ![647898b8c927b](serve/attachment&path=647898b8c927b) I know that the sensor is working since when i connect it the same way to another datalogger(Meier-NT ADL-MX) it works. Here is the output when trying to query the sensor with P56=4: ``` DT85> 1modbus(ad2,R3:30003) 1modbus(ad2,R3:30003) Modbus TX >SS: 02 04753200018a3a (8) Modbus timeout dataTaker 85 E124 - Modbus transaction failed 1MODBUS NotYetSet ``` Is there any other way to debug or am i doing something wrong?

I solved it. The wiring was incorrect -.- i had to switch A and B.

I solved it. The wiring was incorrect -.- i had to switch A and B.

Thanks for the update scholse1,

We are sorry for the late response.

The wiring of RS485 may have different meanings on labels from each manufacturer especially when they use A and B labels, but one thing remains the same when using polarity labels + and -.

Best regards,
dataTaker Expert

Thanks for the update scholse1, We are sorry for the late response. The wiring of RS485 may have different meanings on labels from each manufacturer especially when they use A and B labels, but one thing remains the same when using polarity labels + and -. Best regards, dataTaker Expert
36
2
2
live preview
enter atleast 10 characters
WARNING: You mentioned %MENTIONS%, but they cannot see this message and will not be notified
Saving...
Saved
With selected deselect posts show selected posts
All posts under this topic will be deleted ?
Pending draft ... Click to resume editing
Discard draft