1 Overview
CP340/CP341/CP440/CP441 Communication and Programming
Entry-ID: 88867653, V1.0, 02/2014
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Overview
Siemens SIMATIC S7-series serial communication modules mainly include CP340,
CP341, CP440-1, CP441-1/2, as well as 1SI 3964/ASCII and 1SI MODBUS/USS of
ET200S, etc., and the communication protocols they support mainly include ASCII,
RK512, 3964(R), MODBUS Master, MODBUS Slave and other loadable protocols,
etc. SIMTIC S7-series serial communication modules and their supported
communication protocols are in the corresponding relations shown in the table
below:
ASCII
3964(R)
RK512
MODBUS Master
MODBUS Slave
CP340
X
X
-
-
-
CP341
X
X
X
X
X
CP440
X
X
-
-
-
CP441-1
X
X
-
-
-
CP441-2
X
X
X
X
X
X: support, -: not support
Table 1: Corresponding relations between modules and protocols
In actual application, the above-stated serial communication modules may be used
to realize serial communication for the following devices:
3rd-party DCS and PLC systems, etc.
3rd-party intelligent device and instrument, etc.
Receiving data from scanner and bar-code reader, etc.
Sending data to serial printer and other receiving devices
All other user-defined protocol devices that support ASCII and MODBUS
This document mainly introduces applications of CP340, CP341, CP440, CP441-1
and CP441-2, as well as ASCII, MODBUS RUT protocols they support, and it also
includes the routine used by each module for reference for readers.
Declaration:
The virtual project stated in this document has major difference from
the real project example, and the example is not programmed in accordance with the
specified engineering design flow, and readers shall not confuse it with the real
project example. The example is free of charge, and any user may copy or release it
freely. The author of the program will not assume any liability for any functionality or
compatibility, and users shall assume the related risks. Siemens will not provide error
correction of this program example or hotline support. It is suggested that users