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7 Serial Communications
NX-series Communications Interface Units User’s Manual (W540)
7-4 Examples of Communications between CPU Unit or Communications Master and CIF Unit
7
7-4-1 Example of Sending Data
7-4 Examples of Communications
between CPU Unit or Communica-
tions Master and CIF Unit
If the system configuration does not allow you to use serial communications instructions for CIF Units,
you must program processing for the serial communications protocol in the user program.
This section provides examples that use communi
cations between a CPU Unit or communications
master and CIF Unit.
Precautions for Correct Use
Refer to 1-4-2 Conditions for Using Serial Communications Instructions for CIF Units on page
1-8 for detailed conditions on using the serial communications ins
tructions for CIF Units.
In this example, the following 26-byte text string is sent: ABCDEFGHIJKLMNOPQRSTUVWXYZ.
The text string is separated into the first 20 bytes (ABCDEFGHIJKLMNOPQRST) and the remaining 6
bytes (UVWXYZ) to output it from the CPU Unit or communications master to the CIF Unit.
For a programming sample for this example, refer to A-4-3 Programming Sample 2: Sending Data on
pa
ge A-35.
Here, we will assume that the input notification data and
output notification data are in the following
default status before the data is sent. The default status will exist immediately after the power supply to
the Controller is turned ON or the CIF Unit is restarted.
Input Notification Data
Output Notification Data
7-4-1 Example of Sending Data
NX object name Value
Port Status Depends on port status.
Input SID 00 hex
Output SID Response 00 hex
Input Data Type 0000 hex
Input Sub Info 0000 hex
Input Data Length 0000 hex
Input Data 01 00 hex, 00 hex, 00 hex, 00 hex
NX object name Value
Output SID 00 hex
Input SID Response 00 hex
Output Data Type 0000 hex
Output Sub Info 0000 hex
Output Data Length 0000 hex
Output Data 01 to 05 00 hex, 00 hex ...
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