mbo - Modbus Object

The modbus.set function will return a Modbus Object (mbo) that can be used for abbreviated calls to the Modbus library.

e.g.

cp3 = serial.port(3)

mbo = modbus.set(cp3, '38400N8')
…

local t = mbo:rir(246,2000,10,'WWF+') -- Read from VEGA C 23 Radar
-- t[1] = Status
-- t[3] = PV
-- t[4] = SV
-- t[5] = TV
-- t[6] = QV

This is identical to:

cp3 = serial.port(3)

modbus.set(cp3, '38400N8')
…

local t = modbus.rir(cp3, 246,2000,10,'WWF+') -- Read from VEGA C 23 Radar
…

Internals

The mbo is just a Lua table with the following fields:

`mbo` field	Description
`cpo`	COM Port Object
`__metatable`	Metatable that points `__index` to `modbus`

Reference

See the Modbus Application Protocol Specification for details on the protocol.
Modbus_Application_Protocol_V1_1b3.pdf