No-Protocol Communications With General Components; Overview - Omron CP1E CPU UNIT SOFTWARE User Manual

14 Serial Communications
14-3 No-protocol Communications with
General Components
No-protocol communications can be used only with the CP1E N/NA-type CPU Unit.

14-3-1 Overview

CP1E CPU Units and general devices with serial communications ports can be used for no-protocol
communications.
No-protocol communications enable sending and receiving data using the TRANSMIT (TXD) and
RECEIVE (RXD) instructions without using a protocol and without data conversion (e.g., no retry pro-
cessing, data type conversion, or process branching based on received data).
The serial communications mode is set to RS-232C.
CP1E N/NA-type CPU Unit
Sending/
receiving data
General component
(e.g., barcode reader)
No-protocol communications are used to send data in one direction to or from general external devices
that have an RS-232C or RS-422A/485 port using TXD or RXD.
For example, simple (no-protocol) communications can be used to input data from a barcode reader or
output data to a printer.
The following table lists the no-protocol communication functions supported by CP1E PLCs.
Communica- Transfer
tions direction
PLC →
Data
transmission External
device
Data External
device →
reception
PLC
14-8
TXD or RXD
RS-232C or RS422A/485
Max.
Method amount of
Start code
data
Execution 256 bytes Yes: 00 to FF
of TXD in hex
the ladder No: None
program
Execution 256 bytes
of RXD in
the ladder
program
Frame format
End code
Yes: 00 to FF • Send delay time (delay
hex or CR+LF between TXD execution and
No: None (The sending data from specified
amount of data port): 0 to 99,990 ms at the
to receive is minimum(unit: 10 ms)
specified
• Controlling RS and ER signals
between 1 and
Monitoring CS and DR signals
256 bytes when
no end code is
specified.)
CP1E CPU Unit Software User's Manual(W480)
Other functions