Rockwell Automation 61C365 4 Output 4-20mA Analog Rail - Manual (Page 23)

4Ć1
4.0 PROGRAMMING
This section describes how the data is organized in the module and
provides examples of how the module is accessed by application
programs.
When creating application programs, the programmer must estimate
the magnitude of output data because it must be in the specified
range of the Analog Rail module (0Ć4095).
Recall that at a digital output = 4096, the output rolls over to zero
again. The programmer must include limits in the application
software to ensure that the data sent to output channels is always in
the allowable range.
4.1 Analog Rail Module in AutoMate Systems
This section describes how the Analog Rail is used with AutoMate
systems. Local Head mode allows all four channels on the module
to be updated at the end of the scan (normal I/O update rate in this
configuration), or during the scan using AOUT blocks (see section
4.1.4). Rail mode allows only one channel to be updated at the end
of the scan (normal I/O update rate in this configuration), or all four
channels to be updated during the scan if AOUT blocks are used.
4.1.1 Configuring the AutoMate Processor for
Use with the Analog Rail Module
Configuration is the process of describing in software how the
hardware and software in the system are related. The Analog Rail
module is configured using the AutoMate Programming Executive
(APX) software, M/N 45C130 or 45C131. Select CONFIGURE
SYSTEM from the main menu to create the configuration.
Note that the Analog Rail module can also be configured using the
AutoMate Programming System (APS) software, M/N 45C134,
45C141, 45C142, or 45C143. Refer to instruction manual J2Ć3041 for
additional information.
The Analog Rail module is configured depending upon the mode in
which it is being used. See figures 4.1, 4.2, 4.3, 4.4, and 4.5 for how
to configure the Analog Rail for use with AutoMate processors. The
sample configurations are shown as they appear on the APX screen.
Unless otherwise noted, all references to the AutoMate 20, 30, and
40 will also apply to the 20E, 30E and the 40E, respectively.