Product manual

TAC Xenta Server – Gateway, Technical Manual B Protocols
Schneider Electric Buildings AB, June 2011 139 (184)
04-00124-06-en
B.3.3 Modbus Slave Devices
One or more slave devices are added to the Modbus TCP interface node
in the network pane of XBuilder, as shown for the Panel slave device of
the IPSim example network in the following screenshot.
Device Template
Device templates having a [Modbus_Ext] filename prefix are used to
create Modbus Slave devices in XBuilder. Subsequently, each device
node is used to configure communications with the physical slave it rep-
resents on the Modbus network.
Device Properties
• Address – Allows the required slave address to be entered. The
entered number should correspond to the unique address of the tar-
get slave on the Modbus network (1 to 247). An address of 0 may
be entered to access values from the Modbus TCP server.
• Max Range Size – Sets the maximum number of registers to be
polled in a single request (1 to 100). Lower values increase the
number of messages needed to poll all the required register values,
whereas higher settings may reduce the number (if supported by
the device). Most devices support at least the default value of 20,
but a few may support less.
Device Status Signal
For each device the Modbus TCP driver generates a communication sta-
tus signal.
• ComsFail – Flags if communications with the slave device have
failed. May be caused by an incorrect device address having been
entered, or by incorrect connection between the device and server.
• online – Flags ONLINE during normal device communications,
and will change to OFFLINE if communications with the slave
device have failed. An OFFLINE condition normally indicates an
incorrect device address having been entered, or by incorrect wir-
ing of the network connection to it.