Rockwell Automation 1770,D17706.5.21 SMART TRANSMITTER TOOLKI - Manual (Page 20)

Chapter 3
3-1
Using The Smart Transmitter Toolkit
Follow the instructions in this chapter to incorporate the STT subroutine
into your ladder code and use the HART commands.
1. Create data table files.
2. Provide the STT subroutine inputs
3. Use the STT subroutine status word.
4. Call the STT subroutine.
5. Interpret the STT subroutine outputs.
At the end of this chapter, you’ll find some programming examples.
In your PLC-5 processor, create one integer and one floating-point file for
each HART field device.
Each integer file must be 150 integer words minimum (0 through 149)
Each floating-point file must be 20 floating-point words minimum
(0 through 19)
In addition, the floating point file must be the data file that immediately
follows the integer data file. For example, if the integer file is N10, the
floating point file must be F11.
Important: The STT utility uses integer data file N90 for indirect
addressing. Do not use this data file for a HART field device data
table file.
Since the STT subroutine uses N90:0 and N90:1 for indirect addressing,
you must place valid file numbers in N90:0 and N90:1. For example, if
you created N10 and F11, you need to place a 10 in data table location
N90:0 and an 11 in data table location N90:1.
Following is an explanation of how the data tables are used by the STT
subroutine.
What's In This Chapter
1. Create Data Table Files
Integer word = 16 bits
FloatingĆpoint word = 32Ćbits