Spectrum Controls 140 AUI 040 00sc - Manual (Page 35)

16-Channel Universal Analog Input Module
37
Chapter 6
APPLICATION NOTES
6.1 General Application Tips
The following is a list of do’s and don’ts that should be observed in your applications.
• Select the appropriate 140 AUI 040 00sc from the I/O map selection screen.
• Configure the module using your programming software, make appropriate use of Configuration and Status registers as
outlined in Chapters 2 through 4.
• Ensure correct units of measure are selected for data type.
• Use the lowest filter frequency setting possible for your application, this ensures the most stable and accurate
readings.
• Configure the 4x Register.
• Check that the Green Ready LED is lit when the module is powered up and has completed its self test.
• Check that the Green Active LED is lit when data is being transferred to the Quantum CPU.
6.2 Demultiplexing Channel Data - Autosequence Mode
The autosequence mode of operation is intended to simplify the demultiplexing of channel data from the eight
input registers into storage for the 16 channels. The autosequence mode is enabled under the following condi-
tions:
• Input Mode = Data Mode (Configuration Word Bits 5 & 6 = 0)
In the autosequence mode, the group select bits in the configuration word are ignored. Instead, the module
samples channel data in groups of eight (8), presents the data to the PLC and then scans the next group
automatically. The ladder logic then reads the status word to determine which data is being presented and
copies the data to the appropriate storage locations for those channels.
The module update rate is determined by the number of channels enabled and the filter frequencies selected.
For example, if all 16 channels are enabled and the filter frequency for all groups is 50/60 Hz, then the cycle
time for a full set of 16 channels is 16 x 73 msec or 1.168 seconds.
It takes two ladder logic scans of the eight registers to see all 16 channels. These two scans must be com-
pleted at least twice as fast as the module update time to ensure no data is missed. In the example above the
ladder scan time would need to run at 1.168 sec/8 or 146 msec or faster to ensure no data is missed.
Refer to Section 6.4 Channel Update Rate for channel update times.
6.3 Using ladder to move data to a block of 16 consecutive registers
The following ladder logic shows how to move data from the 8 multiplexed input words to a block of 16 output
words starting at location 400101 with the autosequence mode disabled. This example file for use only with
Modsoft programming software can be formed on the install disk shipped with your module. The file is under
the A:\Programs subdirectory. To install:
1. Insert the install disk into drive A:
2. Copy A:\Programs\QAI32_AC.* C:\Modsoft\Programs
3. Select File QAI32_AC under Modsoft to run.