Nor-Cal SDC15 Controller - Manual (Page 174)

7 - 8 Cautions when Making Communications
Programs for the Master Station
7-16
Pay attention to the following points when making communications 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 communications 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 smart loader package
SLP-C35 has been installed.
In the default setting, the directory is "c:¥program files¥slp¥slpc35¥cpl.cpp".
The program is written in Borland's C++Builder5.0 or Borland C++Compiler5.5
for Windows95/98/NT/2000.
This program is given here as a reference when the user makes a program, and
does not assure all the operations.
You can download Borland C++Compiler5.5 from Borland Home Page.
Handling Precautions
Yamatake 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.
● Running the sample program
This program is used for reading and writing data. When the program is executed,
the application layers of the instruction message and response message
communicated are indicated.
command:RS,14356W,2
result:00,0,0
command:WS,14357W,2
result:00
Sample indication of execution results
● Processing of the sample program
• Communication settings
Call open() and initialize the RS-232C serial port.
• Command execution
Set a desired character string in 'command' and call AppCPL().
Chapter 7. CPL COMMUNICATIONS FUNCTIONS