HMS Anybus X-gateway Modbus-TCP User Manual page 33

Add Transactions
Transactions represent the data that is read from/written to the servers of the Modbus-TCP network.
The global configuration limits box keeps track of the number of added transactions, the current mini-
mum allowed scan time, and the current amount of mapped process data (input and output data).
To add transactions, find the server in the server list and click 'Transactions'. This presents a list of all
transactions configured for that server. Click 'Add transaction' to add a new default transaction to the
list and click 'edit'.
Available settings:
Setting
Alias
Timeout (ms)
Scan time (ms)
Function code
Data encoding
Unit ID
Starting address
Elements
Data type
Registers
Anybus X-gateway for Modbus-TCP - Modbus-TCP
Doc.Rev. 1.00
Description
While not required, renaming the transaction makes the configuration easier to comprehend. Note
that it is only possible to use uppercase and lowercase characters, numerals and underscore (_)
Default alias is 'New_Trans'
Max length: 12 characters
The time span within which the server must return a response to the transaction
Value range: 10 - 65535 (ms)
The scan time defines how often the transaction shall be resent, e.g. the time cycle of a repeating
transaction
Minimum scan time (ms) is calculated by multiplying the total number of transactions by three
The minimum scan time will increase by adding more transactions
Value range: 10 - 10000 (ms)
The function code defines the purpose of the transaction
Choose from five different Modbus functions, see "Modbus-TCP Functions" on page 24
Decides in what order the different bytes of the received/transmitted data shall be sent on the network
Only applicable for Modbus RTU servers. If the Modbus-TCP server functions as a router to Modbus
RTU servers, it is possible to send transactions to a single Modbus RTU server using the unit ID
Value range: 0 - 247; 255
If not communicating with a Modbus RTU server, use the value 255 (default)
The starting Modbus server register address to write to/read from
Value range: 1 - 65536
The number of elements to write/read
Value range: See "Modbus-TCP Functions" on page 24.
Write/read data either as two byte integers (uint16) or four byte integers (uint32)
The resulting amount of registers to write/read.
The calculation is based on the number of elements to read/write and the chosen data type
Network Configuration 33
Doc.Id. SCM-1200-114