Modbus help

[admin]

If you need to change the unit number dynamically then you should use scripts with a single write of multiple registers. The Modbus device might only handle a small number of parallel TCP connections which leads to communication issues.

Try logging the result of connect/write:

Code:

mb = require('luamodbus').tcp() mb:open('192.168.1.1', 502) res, err = mb:connect() if res then   res, err = mb:writeregisters(1, 2, 3)   if not res then     log('write failed', err)   end   else   log('connection failed', err) end mb:close()