VIPA CP 240 RS232, Manual

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Chapter 4 CP 240 - serial Manual VIPA System 200V
4-32 HB97E - CP - Rev. 11/30
The following text describes the communication options between Modbus
master and Modbus slave with the following combination options:
•
CP 240 Modbus Master
↔
CP 240 Modbus Slave Short
•
CP 240 Modbus Master
↔
CP 240 Modbus Long
Modbus Master
The communication in master mode happens via data blocks deploying the
CP 240 SEND-RECEIVE handling blocks. With the usage of a blockage
you may transfer up to 250Byte user data.
Modbus Slave Short
The Modbus Slave Short mode limits the amount of user data for in- and
output to 16Byte. For this you only need a hardware configuration at the
slave section.
•
Build-up each one System 200V for the master and the slave consisting
of a CPU 21x and a CP 240 for each and connect both systems via the
serial interface.
•
Configure the master section.
The parameterization of the CP 240 as Modbus master happens via the
hardware configuration. Additionally you need a PLC user application for
the communication, build-up with the following structure:
OB 1: Call of FC0 (SEND) with error evaluation. For this the telegram
has to be stored in the send block according to Modbus rules.
Call of FC1 (RECEIVE) with error evaluation. The data is stored
in the receive block according to Modbus rules.
•
Configure the slave section.
The parameterization of the CP 240 happens via the hardware
configuration. Set here the start address for in- and output area from
where on the fix amount of each 16Byte for in- and output are stored in
the CPU at arbitrary place.
System 200V
CPU CP 240 Master
System 200V
CP 240 Slave CPU
SEND
RECEIVE
RECEIVE
code/data
answer telegram
SEND
code
data
cyclical
data transfer
Communication
options
Master
↔ ↔ ↔ ↔
Slave Short
Approach