Chapter
5
5-1
Analog Block Applications Using
Discrete Transfers
In this chapter you will read about:
discrete data transfer
input data format
output data format
When used with SLC controllers, analog block data is transferred as
discrete data using the 1747-SN remote I/O scanner module. The analog
block uses 1/2 rack of memory in the I/O data table. The transferred words
in the input image data table contain only input data from the module.
Discrete transfer programming moves data from the module to the
processor’s data table in one I/O scan. The processor I/O scan initiates the
request to transfer data from the module to the processor.
The input image table data format consists of four words. All four words
are input data for the four input channels as shown in Table 5.A.
Figure 5.1
Discrete Data Transfer Description - Input Table 1/2 Rack
Decimal
15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00
Octal
17
16
15
14
13
12
11
10
07
06
05
04
03
02
01
00
0
Input Channel 0 Data
1
Input Channel 1 Data
2
Input Channel 2 Data
3
Input Channel 3 Data
Chapter Objectives
Discrete Data Transfer
Input Data Format
