Omron TJ2-MC64 - PROGRAMMING Programming Manual page 217

Communication protocols
To access the VR memory area, execute the command ETHERNET(1,-
1,9,0). This is the default setting at power-up. To access the TABLE memory
area, execute the command ETHERNET(1,-1,9,1).
Trajexia can exchange data in the holding registers via the ModbusTCP
protocol. Trajexia supports 16-bit signed integer values and 32-bit IEEE
floating point values. The data format used is defined by a parameter of the
ETHERNET command. To exchange holding registers values as 16-bit
signed integers, execute the command ETHERNET(1,-1,7,0). This is the
default setting at power-up. To exchange holding registers values as 32-bit
IEEE floating point, execute the command ETHERNET(1,-1,7,1).
More information on the Modbus protocol and the communication messages
format can be found in the MODBUS APPLICATION PROTOCOL
SPECIFICATION document, which can be downloaded at
http://www.Modbus-IDA.org.
4.2.5 EtherNet/IP protocol
EtherNet/IP is an industrial multi-vendor network that uses Ethernet
components. The EtherNet/IP specifications are open standards managed
by the ODVA (Open DeviceNet Vendor Association), just like DeviceNet.
EtherNet/IP is not just a network between controllers; it is also used as a
field network. Since EtherNet/IP uses standard Ethernet technology, various
general-purpose Ethernet devices can be used in the network.
The EtherNet/IP protocol supports implicit communications, which allows
cyclic communications with EtherNet/IP devices. Data can be exchanged at
high speed between Controllers and devices. TJ2-MC64 can exchange a
maximum of 512 bytes per end-point.
The meaning of the data is defined when the connection between the client
and server end-points is established.
The client opens a connection with an endpoint on the server (the
Controller). The type of data exchanged is determined by defining the
endpoint on the Controller. The CIP Assembly object, instances 100 (input to
the Controller) and 101 (output from the Controller) are used and mapped to
the required VR or TABLE memory on the Controller. This mapping is
defined at run-time using the ETHERNET command.
PROGRAMMING MANUAL
The memory area on the controller with which the endpoint is associated,
and the format of the data exchanged is determined by configuring
parameters on the endpoint using the ETHERNET command.
The ETHERNET command function index '14' is used to access the
endpoints, as follows:
ETHERNET(action, unit_number, function, endpoint_id,
parameter_index [,parameter_value])
• action
0 = Read, 1 = Write.
• unit_number
-1
• function
14
• endpoint_id
/i
Index Value
1 Assembly Object, Instance 100
2 Assembly Object, Instance 101
• parameter_index, parameter_value
/i
parameter_index
Value Description
0 Address
1 Data type
2 Data format
Examples
Set endpoint 1 to VR data type, and data format to 32 bit floating point:
Description
Input to the controller
Output from the controller
parameter_value
Value Description
-- Start address (default = 0)
3 VR (default)
4 TABLE
0 16 bit integer (default) (2 byte element)
1 32 bit integer (4 byte element)
2 32 bit floating point (4 byte element)
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