Automationdirect.com DirectLOGIC DL205 Series User Manual page 429

Chapter 5: Standard RLL Instructions - ASCII
Managing the ASCII Strings
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The following instructions can be helpful in managing the ASCII strings within the CPUs
V-memory:
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ASCII Find (AFIND) – Finds where a specific portion of the ASCII string is located in
continuous V-memory addresses. Forward and reverse searches are supported.
ASCII Extract (AEX) – Extracts a specific portion (usually some data value) from the ASCII
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find location or other known ASCII data location.
Compare V-memory (CMPV) – This instruction is used to compare two blocks of
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V-memory addresses and is usually used to detect a change in an ASCII string. Compared
data types must be of the same format (i.e. BCD, ASCII, etc.).
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Swap Bytes (SWAPB) – usually used to swap V-memory bytes on ASCII data that was
written directly to V-memory from an external HMI or similar master device via a
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communications protocol. The AIN and AEX instructions have a built–in byte swap feature.
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ASCII Input (AIN)
The ASCII Input instruction allows the CPU to receive ASCII strings through the specified
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230 communications port and places the string into a series of specified V-memory registers. The
ASCII data can be received as a fixed number of bytes or as a variable length string with a
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specified termination character(s). Other features include, Byte Swap preferences, Character
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250-1
Timeout, and user defined flag bits for Busy, Complete and Timeout Error.
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DS Used
HPP N/A
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A
B
C
D
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DL205 User Manual, 4th Edition, Rev. B