Modbus write multiple registers

[Alferov]

Hello!

fw 20160927
  
Modbus

Code:

if not mb then
    mbproxy = require('mbproxy')
    mb = mbproxy.new()
end
mb:setslave(4)

res, err = mb:writemultipleregisters(46165, o1, o2, o3)
if err then log(err); end

Logs: *string: Illegal function

What not so?