Cmd modbus poll serial#
Cmd modbus poll Pc#

Cmd modbus poll serial#

Without such a tool, you're doing blind-debugging.1 Witte Software Modbus Poll User manual Modbus Master Simulator June 2015 Modbus Poll version 6.3 Copyright: Witte Software,Дў Table of content 1 Modbus Poll Modbus Poll Features Connections Supported Modbus Functions Data logging Display formats Miscellaneous features Overview Help from anywhere Alias cells Value cells Change color and font Open a new window Connection dialog Connection Serial Settings Mode Response timeout Min delay between polls Remote Server Advanced settings RTS Toggle DSR CTS DTR Remove Echo Read/Write definition Slave ID Function code Read functions Write functions Address Protocol/message address Device address digits vs. As I stated in my comment, I recommend using a logic analyzer to see what's going on on the wire. If you still get timeouts with registeraddress = 45, your Python runtime may have some problems accessing the serial port. A request to access an unaligned data (with a wrong register value) can be simply rejected by the firmware. Maybe a request to access the temperature register actually triggers some measurement function and then returns a value. But we can't know how the device works internally. So when using this library, you need to use registeraddress = 45 for accessing the temperature, not 46 or 40046.Д«ut why won't 46 work? Normally, one would expect it to grab data starting from the next register and print some garbage, but not timeout. I think it's safe to assume that both use the same addressing which starts from 1, as the command-line tool has no problems accessing the value.Д«ut MinimalModbus API clearly mentions that its register start address is 0. But its documentation mentions that the default value for -r parameter is 1. Similarly, the mbpoll command-line utility (not the one with GUI) isn't very clear about the start address. The device manual isn't clear about the register start address, but the first register it mentions has the address of 1. Temperature = instrument.read_long(registeraddress=9001, functioncode=3,Д«yteorder=0) # Registernumber, number of decimals

I apologies for my armature code but the solution that works for me is the below - import minimalmodbus As semi-alluded to in other suggestions the device I am connecting to has a 'sleep' period or the like and needs to be polled once, unsuccessfully, before successfully returning values for any subsequent polls. Just updating with the solution if anyone happens to stumble upon this and has the same problem. I have also tried depth = instrument.read_long(x, x) with different values I am not married to minimal modbus - I am happy to use any tool to get this done Register is 40046, so I understand this to be register 45 of the holding registers? How do I translate this to minimalmodbus? I am able to read a register using Modbus Poll. I have tried to incorporate minimal modbus structure but to no avail.

Cmd modbus poll Pc#

Temperature = instrument.read_float(registeraddress=45, functioncode=4, number_of_registers=2, byteorder=0) # Registernumber, number of decimalsДevice is a Level Troll 400 Connected to PC via manufactures cable #nstrument.clear_buffers_before_each_transaction = True Temperature = instrument.read_float(registeraddress=40046, functioncode=3, number_of_registers=2, byteorder=0) # Registernumber, number of decimals Instrument.clear_buffers_before_each_transaction = True Instrument.mode = minimalmodbus.MODE_RTU # rtu or ascii mode Instrument.address = 1 # this is the slave address number Instrument = minimalmodbus.Instrument('COM5', 1) # port name, slave address (in decimal)

My code is as follows - import minimalmodbus (Address different as running on Pi not PC) Register is readable in mbpoll using - mbpoll -B -m RTU -t 4:float -a 1 -b 19200 -r 46 -c 2 /dev/ttyUSB0

I am getting no response from the instrument. I have confirmed the COM port, Baud rate and other communication settings and I can use the devices application to read the value (it is a water level logger). I am trying to use Python (Pењњharm) to read a register on a modbus device.