Jetter JC-120MC, Руководство пользователя

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Jetter AG 455
JC-120MC Programming
10.15.2 Modbus/TCP client
The Modbus/TCP client included in JC-120MC supports only Class 0
Conformance.
In this class, commands for reading and writing multiple registers are used. Up
to 125 registers with a width of 16 bits can be transmitted in one frame.
As protocol ID "0" is used. Assignment of sent and received frames is carried
out using the transaction ID.
This chapter describes how to carry out noncyclical or cyclical transmission to
a Modbus/TCP server using system functions.
Connections to eleven different Modbus/TCP servers may be opened at the
same time.
System functions 65 and 67 reading registers , as well as 66 and 68 writing
registers are used to establish a noncyclical transmission channel to a
Modbus/TCP server.
These system functions establish a connection to the specified Modbus/TCP
server, transmit the desired data and clear down the connection.
If RemoteScan has already established a connection for cyclical data
transmission, this connection will be used. Setting up and clearing down the
connection is, therefore, not required.
Cyclical data transmission is made through the configurable function
RemoteScan . The inputs and outputs 20001 through 36000 that are
combined in the 16-bit registers 278000 through 278999 are cyclically
transmitted from and to the Modbus/TCP servers.
Only one connection is established to each Modbus/TCP server (IP address
and port) irrespective of the number of communication units which have been
configured on this server.
If several communication units are configured on one Modbus/TCP server,
accesses are serialized since servers often do not support command
pipelining . If several servers have been configured, communication is carried
out in parallel.
Register Inputs and outputs
278000 20001 ... 20016
278001 20017 ... 20032
278002 20033 ... 20048
... ...
278999 35985 ... 36000
These registers and the inputs and outputs mapped to them are merely
storage cells within the RAM. There is no direct mapping to the hardware.
Therefore, it is not defined whether inputs or outputs are mapped to a register.
Assignment is made not until configuration in the communication units takes
place.
Introduction
Number of possible
connections
Noncyclical data
transmission
Cyclical data
transmission
Combined inputs and
outputs