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Siemens TX-I/O Engineering and installation guide CM110562en_13
Building Technologies Introduction 2019-05-15
1.5 TX-I/O™ terms and definitions
Term
Description
Bus master
Device with supervisory function for an assigned set of I/O devices.
Desigo TRA: Room automation station;
DESIGO V4: automation station or bus interface module (BIM);
DESIGO V2.37: P-bus interface module (BIM);
Simatic S7: PROFINET BIM
Island bus
(TX-I/O module bus)
• Communications bus between the bus master (room automation station, automation
station or bus interface module) and the connected TX-I/O modules.
• Simultaneously carries the supply voltages for the modules and the field devices
• The bus is created automatically through the interconnection of the TX-I/O modules.
Island bus expansion
The island bus expansion modules allow “decentralized” sub-islands using TX-I/O
modules that can be located up to 2 x 200 m from each other.
Power supply module "Active" power supply module that converts AC 24 V to DC 24 V. It supplies power for
operation of the module electronics and of DC 24 V and AC 24 V field devices)
Bus connection module "Passive" module which passes communication signals and DC 24 V between multiple
I/O rows and/or serves as a connection point for additional AC / DC
12 … 24 V supply for field devices.
Bus interface module (BIM)
Interface between the island bus and another bus. Acts as an island bus master.
P-bus BIM
Interface between a P-Bus automation station (Desigo, Unigyr, Visonik) and the
island bus.
PROFINET BIM
Interface between a PROFINET system and the island bus.
I/O island All TX-I/O devices that are physically connected to the same island bus segment and
linked to the same bus master.
Sub-island
Local, remote, decentralized sub-islands: see sections 10.5.2, 10.6.5
I/O row One I/O island may consist of several rows of modules, each referred to as an "I/O row".
Each I/O row starts either with a bus master, or a power supply module, or a bus
connection module.
I/O module (assembly) Device in which the physical signals from the field devices are converted into software
process values and vice versa.
An I/O module has a specific number of I/O points, determined by the module type.
The I/O module assemblies (normally called I/O modules) consist of a terminal base and
a plug-in module.
I/O point Smallest addressable unit in an I/O module.
One or more I/O points (e.g. three-stage switching output) correspond to each data point
/channel on the room automation station / the automation station.
Terminal
The cables of the field devices (field devices) are connected to the terminals.
Plug-in module The plug-in component with the module electronics that can be removed from the terminal
base.
Terminal base The base unit for the TX-I/O module, which is mounted on the standard mounting rail and
to which the wiring is connected. The terminals have the function of control panel terminal
strips.
Address key Accessory, which must be plugged into the plug-in module. The module address is
assigned via the mechanical coding of the key.
Reset key Serves to reset the module function to the factory state.
Is inserted in place of the address key and can then be removed.
I/O function The function of an I/O point, which determines how it operates (e.g. signal input, 0…10 V
voltage output etc.).
Certain functions may use more than one I/O point (e.g. multi-stage switching output).
Signal type
Designation of the signal of a physical input / output
TRA
Desigo Room Automation
Addressing From the perspective of the building automation and control system, the module address
consists of a module number (range 1…120) and an I/O point number (range 1…16).
Local override, tool override,
"functional test" etc.
Each BACS has its own tools.