ICP DAS USA I-7521, User Manual

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I-7521/I-7522/I-7522A/I-7523/I-7524/I-7527 User’s Manual,Ver2.5 Aug.2015
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6.2. Typical Applications
Application 1: Addressable RS-232 Controller (Command Type)

Each I-7521 module has a unique address

The Host PC first sends a command to all I-7521 module

The destination I-7521 module will pass the command to its local
RS-232 device

The destination I-7521 module will then send the response from the
RS-232 device back to the Host PC

Refer to the 7521.c file for the source code of the firmware
I-7520
I-7521
(#01)
RS-232
RS-485
Host PC
I-7521
(#02)
I-7521
(#AA)
HP34401A HP34401A HP34401A
Application 2: Addressable RS-232 Controller (Receive Data only
Type)-Barcode Reader1

The barcode-reader can scan a barcode at anytime, and the I-7521
module will store these barcodes in an internal buffer (1K bytes)

The Host PC first sends $AAU command to all I-7521 modules. The
destination I-7521 module will check its internal buffer. If there are any
barcodes in the buffer, the I-7521 module will then send a single
barcode back to the Host PC.

The Host PC can send more $AAU commands to read each barcode
stored in the internal buffer of the I-7521 module

Refer to the 7521.c file for the source code of the firmware