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Chapter 7. CPL COMMUNICATION FUNCTION
Pay attention to the following points when making communication programs:
• The longest response time on the device is two seconds. For this reason, set the response monitor time to two
seconds.
• Resend the same message if there is no response within two seconds. Set a communication error to occur if
there is no response even after two retries.
• Be sure to make the above resends to guard against the case when the message cannot be send correctly due to
the influence of noise, for example, during communications.
Note
When the master station resends the message, alternatively use the device ID codes
"X" and "x." This is convenient as you can tell whether or not the received message
is the previously received message.
Example of communications program
A sample program is installed in the folder in which the SLP-C35 Smart Loader
Package has been installed.
In the default setting, the directory is "c:¥program files¥slp¥slpc35¥cpl.cpp".
This program is written in C++. Microsoft’s Visual C++ 2008 can be used to
compile it.
The program is supplied for purposes of reference to assist the user in making a
program, and its operation is not 100 % guaranteed.
You can download Visual C++ 2008 Express Edition from the Microsoft website at
http://www.microsoft.com/express/.
Handling Precautions
Azbil Corporation assumes no responsibility with regard to any trouble caused
by using this program.
Prior to running the sample program
Make sure to check the settings for communications type, station address,
transmission speed and data format of the instrument.
Compiling
At the Visual Studio 2008 command prompt, enter “cl” to begin compiling.
Example of compilation result
C:\sample>cl cpl.cpp
Microsoft(R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80x86
Copyright (C) Microsoft Corporation. All rights reserved.
cpl.cpp
Microsoft (R) Incremental Linker Version 9.00.30729.01
Copyright (C) Microsoft Corporation. All rights reserved.
/out:cpl.exe
cpl.obj
7 - 8 Cautions when Making Communication Programs for the
Master Station
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