Modbus function code 23 (#17)

[alb-smith]

Does LM support the Modbus function code 23 with profiles or with a script (luamodbus)?
Thanks.

[admin]

See this: https://forum.logicmachine.net/showthrea...4#pid13244
Are you sure that function 23 is needed? Usually you can do writing and reading separately.

[alb-smith]

Thanks for the answer.
User manual of this device seems to require FC 23 as you can see in the picture.
It's a Modbus interface for Mastervolt Battery charger (https://www.mastervolt.it/prodotti/maste...interface/)

[alb-smith]

When trying to implement communication with this device I always get the error "Bad file descriptor".
This LM uses both Modbus RTU ports with a different configuration.

Code:

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require('luamodbus') buffer = {} function logger(c) table.insert(buffer, c) end local mb2 = luamodbus.rtu() mb2:open('/dev/rs485-2', 19200, 'E', 8, 1, 'H') mb2:connect() mb2:setslave(1) mb2:setdebug(logger) values,err=mb2:writereadregisters(0,6,12,0x0A,0x1AE0F,0x0,0x1) log(table.concat(buffer)) mb2:close()

This is the RTU port configuration:

[admin]

RS must be uppercase in the port name.

[alb-smith]

I partially solved it using the send() function sending a string to the device.
In debug I can see the response which is complete and correct but the mb:receive() function returns a timeout error.

Code:

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require('luamodbus') function hexToString(hex)     -- Remove any spaces or invalid characters     hex = hex:gsub("([^0-9a-fA-F])", "")         -- Convert each pair of hex digits into a character     local str = ""     for i = 1, #hex, 2 do         local byte = hex:sub(i, i + 1)         str = str .. string.char(tonumber(byte, 16))     end     return str end buffer = {} function logger(c)     table.insert(buffer, c) end local mb2 = luamodbus.rtu() mb2:open('/dev/RS485-2', 19200, 'E', 8, 1, 'H') mb2:connect() mb2:setslave(1) mb2:setreceivetimeout(1.0) mb2:setresponsetimeout(1.0) mb2:setdebug(logger) local variable_number = '11'  -- in hexadecimal hex_decoded = hexToString("011700000006000000060c0a01ae0f000000" .. variable_number .. "00000000") -- Sending variabile,err_s=mb2:send(hex_decoded) -- Response local response,err = mb2:receive() -- Log the sending operation if variabile then     log("Is send successful?: ")     log(variabile) else     log("Sending error: "..err_s) end -- Log the response if response then     log("Response from device: " .. table.concat(response, ", ")) else     log("Response error: ".. err_r) end log(table.concat(buffer)) mb2:close()

Logs report:

Response error: Operation timed out

Debug:
* string: [01][17][00][00][00][06][00][00][00][06][0C][0A][01][AE][0F][00][00][00][11][00][00][00][00][91][AF]
Waiting for a indication...
<01><17><0C><0A><01><AE><0F><00><00><00><11><00><00><00><42><C1><35>ERROR Operation timed out: select

The response captured by debug is complete and correct.
I tried to change setreceivetimeout() and setresponsetimeout() with no effects.

[admin]

You can't use receive for master operation. The equivalent of your raw string using writereadregisters is this:

Code:

1

mb:writereadregisters(0, 0x0A01, 0xAE0F, 0, 0x0011, 0, 0, 0, 6)