Bus interface Modbus RTU


Volume flow controller – static transducer

Volume flow controller – static transducer


X-AIRCONTROL Modbus zone module

Room control

RJ12 socket


Control component for series TVE and TVE-Q



Control component with static transducer and Modbus RTU interface for X-AIRCONTROL

Compact unit for VAV control unit TVE and TVE-Q

  • Controller, static effective pressure transducer and actuator in one casing
  • Use in ventilation and air conditioning systems, with clean and contaminated air
  • Simple RJ12 connection socket for supply voltage and network
  • Compatible with the X-AIRCONTROL zone module Modbus
  • Volume flow rates qvmin and qvmax are pre-set in the factory and saved in the controller as variable parameters
  • High data transparency via standardised bus communication Modbus RTU, RS485
  • Setpoint value settings, override controls, parameter adjustment via Modbus register
  • Integrated display for volume flow rate display, operating status display and setting of operating parameters
  • Service access for manual adjustment devices and PC configuration software

Allgemeine Informationen


  • All-in-one control devices for VAV terminal units types TVE and TVE-Q
  • Static differential pressure transducer, electronic controller, and actuator are fitted together in one casing
  • Static pressure transducer for extended application range with clean and polluted air, e.g. in exhaust air areas with dust, lint, sticky, moist or slightly aggressive components
  • Various control options based on setpoint value default setting
  • Suitable for X-AIRCONTROL room control, Modbus zone module

  • By specifying setpoints via the communication interface, the control circuits for e.g. temperature, humidity, air quality control the variable air volume flow

  • Simple connection for supply voltage and network with one shared RJ12 connection socket

  • Override controls for activating qvmin, qvmax, shut-off, OPEN are possible using the Modbus register

  • The actual volume flow rate value is available as a network data point
  • The damper blade position is available as a network data point

Control strategy

  • The volume flow controller works independently of the duct pressure
  • Differential pressure fluctuations do not result in permanent volume flow rate changes
  • To prevent the control from becoming unstable, a dead band is allowed within which the damper blade does not move.
  • Flow rate range is set in the controller at the factory (qvmin: minimum volume flow rate, qvmax: maximum volume flow rate)
  • Operating parameters are specified via the order code and set in the factory

Operating modes

  • Modbus (M): setpoint value default via X-AIRCONTROL

Communication interface

  • Modbus RTU, RS 485
  • Data point list see Modbus register list

Parts and characteristics

  • Transducer for static measurements
  • Overload proof actuator
  • RJ12 connection socket with cover
  • Display and control elements for easy menu navigation
  • Menu navigation allows for adjusting operating parameters and communication interface
  • Service interface


  • TR0VM-024T-05I-DS10-MB with RJ12 connection socket
  • Can only be used for type TVE and TVE-Q


  • Due to the volume flow rates set in the factory, always ensure that the control units are only installed in the specified locations
  • Commissioning steps for network integration required
  • Operating parameters can be adjusted by the customer (using the display, adjustment device or Modbus register)

Useful additions

  • Adjustment device type GUIV3-M (order code AT-VAV-G3)
  • Room control X-AIRCONTROL with zone module Modbus type X-AIR-ZMO-MOD

Technical information

Function, Specification text, Order code

  • Function
  • Specification text
  • Order code

1 Differential pressure transducer
2 Actuator
3 Volume flow controller
4 Setpoint value via BACnet, Modbus or analogue signal
5 Shaft with effective pressure channel

Air terminal units control the volume flow in a closed loop, which means: measurement – comparison – adjustment.
The volume flow rate is obtained by measuring a differential pressure. This is done with a differential pressure sensor. The integrated differential pressure transducer converts the differential pressure into a voltage signal. The actual volume flow value is available as a data point. Due to the factory adjustment, 100% always equals the nominal volume flow rate (qvNom).
The volume flow setpoint value is specified by a higher-level controller (e.g. room temperature controller, air quality controller, central BMS). Variable volume flow control can be set between qvmin and qvmax. It is possible to override the room temperature control by forced switching, e.g. for a shut-off
The controller compares the differential pressure setpoint value to the actual value and controls the actuator accordingly if there is a difference.


  • Compact controller for volume flow rate
  • Control of a constant or variable volume flow rate setpoint
  • Electronic controller for connecting a reference variable and tapping an actual value for integration into X-AIRCONTROL
  • The actual value relates to the nominal volume flow rate so that commissioning and subsequent adjustment are simplified


  • Static transducer for polluted air in ventilation and air conditioning systems

Supply voltage

  • 24 V AC/DC


  • Integral; slow-running (running time 100 s for 90°)

Installation orientation

  • Not critical


  • Modbus RTU (RS-485)


  • RJ12 connection socket for easy connection to X-AIRCONTROL, with rubber cap cover
  • Suitable for X-AIRCONTROL zone module X-AIR-ZMO-MOD

Interface information

  • Modbus: among other things, volume flow setpoint and actual value signal, damper position, override control

Special functions

  • Clearly visible external indicator light for indicating the functions: Set, not set, and power failure
  • Display for actual values, parameter setting and for test functions
  • Activation qvmin, qvmax, closed, open by X-AIRCONTROL

Parameter setting

  • Parameters specific to the VAV terminal unit are factory set
  • Operating values: qvmin, qvmax are factory set
  • Subsequent adjustment via display and operating element directly on the unit or with optional tools: Setting device, PC software (each wired), in Modbus mode also via Modbus register access

Factory condition

  • Electronic controller factory-mounted on the terminal unit
  • Factory set parameters
  • Functional test under air; certified with sticker

TVED / 200 / D2 / XS0-J6 / M / qvminqvmaxm³/h
1 Type
TVE VAV terminal unit

2 Acoustic cladding
No entry: without acoustic cladding
D with acoustic cladding

3 Material
No entry: Galvanised sheet steel (standard construction)
P1 Air duct powder-coated RAL 7001 (silver grey)
A2 Stainless steel duct

5 Nominal size [mm]
100, 125, 160, 200, 250, 300, 400

6 Accessories
No entry: none
D2 Double lip seal both ends
G2 Matching flanges both ends

7 Attachments (control component)
XS0-J6 Volume flow controller, Modbus RTU interface, display, RJ12 socket (for X-AIRCONTROL)

8 Operating mode
Modbus RTU interface, variable operation (setpoint specification via Modbus register)

9 Operating values for factory setting
Volume flow rate [m³/h or l/s]
qvmin – qvmax

10 Volume flow rate unit
l/s Order example: TVE–D/200/D2/XS0-J6/M/20-350 m³/h
Acoustic claddingwith acoustic cladding
MaterialGalvanised sheet steel
Nominal size [mm]200
AccessoriesDouble lip seal both ends
Attachment (control components)Compact controller volumetric flow, static transducer, Modbus RTU interface, display, RJ12 connection socket (for X-AIRCONTROL)
Operating modeModbus RTU interface, variable operation
Operating values for factory setting20 – 350
Volume flow rate unitm³/h


  • Variants

  • TVE

Technical data

  • Technical data

Compact controllers for VAV terminal units

VAV terminal unitsType of installation component

Part number




Compact controller TR0VM-024T-05I-DS10-MB with RJ12 socket

Type of measurement/installation orientation

static measuring principle, position-independent

Supply voltage (AC)24 V AC, ± 20 %, 50/60 Hz
Supply voltage (DC)24 V DC ± 20 %
Power rating (AC)TVE NW 100 - 160: maximum 4 VA
TVE NW 200 - 400: maximum 7 VA
TVE-Q up to height 200: maximum 4 VA
TVE-Q from height 300: maximum 7 VA
Power rating (DC)TVE NW 100 - 160: maximum 2.5 W
TVE NW 200 - 400: maximum 4 W
TVE-Q up to height 200: maximum 2.5 W
TVE-Q from height 300: maximum 4 W
Power consumption (when running/when idle)

1 W

Run time for 90°100 s
Setpoint value signal input (analogue optional)0 - 10 V DC, input resistance > 100 kΩ
or 2 - 10V DC Ra> 50 kΩ
Actual value signal output0 - 10 V DC or 2 - 10 V DC; maximum 0.5 mA
IEC protection classIII (Protective extra-low voltage)
Protection levelIP 42 (with attached terminal cover)
EC conformityEMC to 2014/30/EU
Bus connectionModbus RTU, RS485
Number of nodes128
Adjustable communication parameters1200 – 115,200 Bd
Start bit: 1
Data bits: 8
Stop bits: 1 or 2
Parity: None, Even, Odd
Setpoint / actual value interface (Modbus)

Via X-AIRCONTROL/Modus register list

Cable terminationexternally required


Interface configuration of the control component

The communication interface of the control component is preset at the factory for use with the X-AIRCONTROL zone module Modbus. Only the Modbus address must be set by the customer, depending on the use in the supply air and extract air. For other applications, data transmission speed and format must be adapted on site according to the network environment.


Setpoint value default setting via:Actual values via:corresponds to order key optionMenu configuration (Mode)
Analogue operation *analogue 0 - 10 Vanalogue 0 - 10 VV or FCA0
Analogue operation *analogue 2 - 10 Vanalogue 2 - 10 VV or FCA2
Modbus operationModbus register setpointModbus register actual value or analogue 2 - 10 VMCB

* It is not possible to use the analogue interface in combination with the RJ12 connection socket used with the XS0-J6 variant. Therefore, the configuration register (interface mode) must not be changed on site. To use an analogue interface, the XS0 variant is used.

Communication interface Modbus RTU (operating mode M)


MeaningAccess rightStorage

Volume flow setpoint [%]
Reference: Vmin – Vmax (qvmin – qvmax)
Resolution: 0 – 10000
Volume flow setpoint: 0.00 - 100.00%
1Activation of an override control; 0 = none; 1 = Open; 2 = Close; 3 = Vmin; 4 = VmaxR, WRAM
2Command triggering 0 = none; 1 = adaptation; 2 = test run; 4 = controller resetR, WRAM
4Current damper blade position [%]
Resolution: 0 – 10000
Damper blade position: 0.00 – 100.00%
5Current damper blade position [°]
Reference: without decimal places
6Current actual volume flow [%]
Resolution: Vnom
Resolution: 0 – 10000
Actual volume flow rate: 0.00 - 100.00%
7Actual volume flow rate in volume flow rate unit [m³/h], [l/s], [cfm] according to register 201RRAM
8Voltage at analogue input Y [mV]
Note: Connection terminal for analogue input Y not accessible with variant with connection socket


Volume flow setpoint
in volume flow unit [m³/h], [l/s], [cfm] acc. to register 201

R, W


103Firmware versionR

0.00 – 100.00 %
104Status information
(Bit = 1 active; Bit = 0 inactive)
Bit 5 mechanical overload
Bit 8 internal activity e.g. test run, adaptation
Bit 10 bus timeout monitoring triggered
105Operating range limitation: Operating parameter Vmin (qvmin) [%]
Resolution: Vnom
Resolution: 0 – 10000
Vmin: 0.00 – 100.00%
106Operating range limitation: Operating parameter Vmax (qvmax) [%]
Resolution: Vnom
Resolution: 0 – 10000
Vmax: 0.00 – 100.00%
108Behaviour on bus failure (bus time-out); 0 = nothing; 1 = closed; 2 = open; 3 = qvmin; 5 = qvmaxR, WEEPROM
109Setting bus time-out [s]R, WEEPROM
120Definition of operating range: operating parameters Vmin (qvmin) in volume flow rate unit [m³/h], [l/s], [cfm] according to register 201R, WEEPROM
121Definition of operating range: operating parameters Vmax (qvmax) in volume flow rate unit [m³/h], [l/s], [cfm] according to register 201R, WEEPROM
122Interface definition (Interface mode) For assignment see separate tableR, WEEPROM

130 *

Modbus address (device address)R, WEEPROM
201Volume flow rate unit 0 = l/s; 1 = m³/h; 6 = cfmR, WEEPROM
231Setting of mode:
Bit 0 defines the characteristic of the analogue interface.
Bit 0 = 0 characteristic: 0 – 10 V
Bit 0 = 1 characteristic: 2 – 10 V
Bit 4 defines the actual value signal as actual volume flow rate or damper position.
Bit 4 = 0 Actual volume flow rate
Bit 4 = 1 Damper blade position
All other bits must not be changed.


Nominal flow rate [m3 /h] (Vnom):
Displays the parameterised nominal volume flow rate




Modbus parameter set, communication settings: baud rate, parity, stop bits, assignment see separate table

569Modbus communication settings: Modbus Response Time = 10 ms + delay; with delay= 3 ms × register value 0 - 255R, WEEPROM

* Factory setting: Modbus address 1

R = register readable

R,W = register readable and writable

RAM = register value volatile

EEPROM = register value not volatile, but permanently stored (maximum 1 million write operations)



All registers from register number 100 onwards with storage in the EEPROM are not designed for cyclical write access, e.g. by the building management system. Cyclic write operations are only permitted on registers with storage in RAM.

Detailed information on register 122 (communication interface setpoint/actual value - interface mode)

Register value

Signal inputFeedback signal

analogue (0) 2 - 10 V(0)2 – 10 V
2Modbus via Register 0Register 10
1Modbus via Register 0(0)2 – 10 V
3analogue (0) 2 - 10 VRegister 10


For the control components XM0-J6 and XS0-J6, only register value 2 is useful, as analogue input and analogue feedback signal are not available on the RJ12 connection socket.

Detailed information on register 568 (Modbus communication parameters)

Register value

Display setting valueBaud rateParityStop bits



15 **






** Factory setting: Modbus communication parameters


Note on the type of static transducer used

  • Mounting position any
  • Zero point adjustment not required


After installation, wiring and connection of the supply voltage

  • Set the Modbus communication parameters via the integrated display menu, then the air terminal unit is ready for operation
  • Setpoint specification via Modbus register from X-AIRCONTROL zone module
  • Remove terminal cover of the control component only for wiring


Observe volume flow control ranges

  • TVE: 4 - 100 % of qvnom
  • TVE-Q: 10 - 100 % of qvnom
  • In particular, do not fall below the values for the minimum volume flow of the control unit

Range of display functions

Display functions

  • Actual volume flow rate (unit optionally m³/h, l/s, cfm)
  • 3-character display with positional notation
  • Status and error display for various operating states, including display of activated override control and diagnosis function


Parameter setting

  • Adjustment option for the unit of the volume flow rate display m³/h, l/s, cfm
  • Adjustment option for the operating range qvmin, qvmax
  • Selection of interface configuration Modbus or analogue including signal voltage range 0 - 10 V or 2 - 10 V DC
  • For the variant with RJ12 connection socket, only the Modbus interface configuration is suitable
  • Adjustment option for Modbus communication settings (address, baud rate, stop bits, parity)


Diagnostic functions

  • Activation of a test run
  • Activation of override controls Open, Closed, qvmin, qvmax, motor stop (note prioritisation)
  • Display of the voltage value on the analogue input

Use and description of the display

Pressing the LED button (< 3 s) selects the next menu item (1) - (6). The selected menu item can be changed by pressing the LED push button for more than 3 s. Changing is done with the rotary selector switch. Pressing the LED push button again (< 3 s) confirms the selected value. If no entry is made for ≥ 60 s, the system returns to menu item 1.

Table 1: Description of the menu items
① FlowDisplay of actual values or operating states. Setting of the volume flow unit m³/h, l/s, cfm.
② VminSetting qvmin
③ VmaxSetting qvmax


Display of control signal and feedback signal alternately in [V],
Activation of override controls for test and diagnostic purposes:
tst = test drive
oP = damper open
cL = damper closed
Lo = qvmin
Hi = qvmax
St = motor stop
oFF = override control off
000 = Display firmware version


Selection of the operating mode:
CA0 = Setpoint input and actual value return via analogue interface (0 - 10 V)
CA2 = Setpoint input and actual value return via analogue interface (2 - 10 V)
CB2 = Setpoint input and actual value return via Modbus - optional actual value return via (2 - 10 V)


Setting the Modbus address: 1 - 247

and the baud rate, parity, stop bits: 1 (b1) - 32 (b32)

Note on MODE setting:
For the control component XM0-J6 or XS0-J6, only the mode setting CB2 is useful, as setpoint input and actual value return as analogue signal are not available on the RJ12 connection socket of these control components.

Description of status LEDs and error messages

LED flashing signalStatusDisplay

no power supply connected

Service tool plugged in.
On-site network connection deactivated.
Forced controls from the service tool have priority

Undervoltage detected.
Supply voltage outside the tolerance range.
Control function not guaranteed

TROX service technicians provide information.
Incomplete parameterisation was detected during power-on/reset *

Drive overload detected (block) *

Synchronisation drive after Power Up *

Test mode enabled *

Overpressure sensor (Overpressure) *

Setpoint or forced control position not yet reached (display changes between e.g. Hi = high and actual value) *

Forced control position reached
(display changes between e.g. Hi = High and actual value) *

Offset: Is signalled as long as the drive does not rotate to readjust the setpoint value *


  1. The signal spans 2 seconds. 1 = LED is illuminated, 0 = LED is not illuminated
  2. For service tool plugged in (display: Pc) and undervoltage detected (display: Lou), no special flashing signal appears on the LED button. Instead, one of the operating states marked with an asterisk (*) is displayed.


product information


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