Setup guide

Chapter 3 Driver and Protocol Objects
©
Automationdirect.com 3-83 Object Reference Manual
Tiway
Tiway is a protocol driver object Lookout uses to communicate with series
5
xx
PLCs manufactured by Siemens, formerly made by Texas Instruments.
Protocol driver objects contain a great deal of data. All readable and
writable members (inputs/outputs), polling instructions, read/write
blocking, serial port usage, and so on are bundled with the object. As soon
as you create a Tiway object you immediately have access to all the object
data members (see data member list in this section).
Note
Lookout protocol driver objects automatically generate an efficient read/write
blocking scheme based on the inputs and outputs being used in your process file. You are
not required to build your own I/O blocking table.
PLC Model specifies the PLC model number for the requested device.
PollRate is a numeric expression that determines how often to poll the
device. Tiway then polls the device at the specified time interval. Normally,
this is a simple time constant such as 0:01 (one second). See
Numeric Data
Members
in Chapter 2,
How Lookout Works, of the Getting Started with
Lookout
manual for more information on entering time constants.
Poll is a logical expression. When this expression changes from FALSE to
TRUE, Lookout polls the device. You can use a simple expression like the
signal from a pushbutton, or a complex algorithm.