VIPA CP 240 RS232, Руководство пользователя

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Manual VIPA System 200V Chapter 4 CP 240 - serial
HB97E - CP - Rev. 11/30 4-33
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 Long
In the Modbus Slave Long mode only a changed data area is transferred to
the CPU via RECEIVE starting with 0. If the master requests data it has to
be made sure that the relevant data are present in the CP. With a SEND
call a wanted data area in transferred to the CP starting with 0 .
•
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 project engineering of the master section happens like shown in the
sample above.
•
Configure the slave section.
The parameterization of the CP 240 as Modbus slave 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. For this an area starting at 0 is
stored in the CP 240 where the master may gain access via
Modbus.
The FC1 (RECEIVE) with error evaluation allows you to transfer
a data area into the CPU. The reception area with a max. size of
1024Byte is separated into 128 8Byte blocks. At a data change
by the master, only those blocks are transferred to the CPU
where changes occurred. During one block cycle of the
RECEIVE block a maximum of 16 coherent 8Byte blocks may be
handled on at the back plane bus. If the 8Byte blocks are not
coherent every changed 8Byte block requires one block cycle.
At call of the RECEIVE block, the receive DB has always to be
set as a multiple of 8. Writing master accesses may not be
outside of the receive area!
System 200V
CPU CP 240 Master
System 200V
CP 240 Slave
SEND
RECEIVE
RECEIVE
code/data
answer telegram
SEND
code
data
..
.
..
.
CPU
SEND
RECEIVE
8Byte
max. 128Byte/block cycle
max. 1024Byte/block cycle
Master
→
→ →
→
Slave Long
Approach