System information

General Reference Guide IO Servers Configuration
RG-001-0-EN ver 1.5 eWON® - 20/03/2009 - ©ACT'L sa Page 89
Example: if Modbus and UniTE IO servers are available, at least one of them must have its baud rate set to Disabled. If not the case,
one of the IO servers will not be able to use the serial line and it will be disabled, with an error written in the event log.
5.3.2.3 Topic configuration
Figure 76: Modbus topics configuration
Three topics can be used for the IO Server. These topics are used to give a common property to a group of MODBUS Tag like:
• Enable/Disable
• Poll rate
• Slave address (Modbus RTU)
• Unit address and TCP/IP address (Modbus TCP)
Warning:
Any slave address that is defined in the Topic configuration overwrites the slave address configured per Tag.
If a Tag is defined with Tag Address: 40010,5 and the global address of the topic is 5 and 10.0.0.81, the Tag is entered as Modbus
RTU but it is polled as Modbus TCP. So, if you need to address slaves Tag by Tag, let the topic address configuration empty.
5.3.2.4 Advanced parameters
Figure 77: Modbus advanced parameters configuration
Extended parameters have been added to accommodate various special operating conditions. They are entered in the edit box at the bottom of
the configuration page, conforming to the syntax below. Each parameter has a default value, so the advanced parameter edit box must only be
filled with the parameters for which default values must be changed. (c.f. “Standard IO server configuration page” page 87).
Modbus Server Properties Description
Topic enabled Enables or disables polling of all the Tags in the topic.
Slave address
The slave address is a global parameter for all the Tags of the topic. If the slave is connected
with Modbus RTU, Slave address must be entered and the IP address must be blank. If the
slave is Modbus TCP, its unit address and its IP address must be entered.
Poll rate
This defines the rate to which the Tag will be refreshed. In a complex application, we can
imagine that some Tags must be refreshed every second – typically for digital input - and
other every minute – typically: temperature-.
Table 57: Modbus topic configuration