FläktGroup Pi Function Modbus Communication (IQAZ-35 ) Installation guide

Brand: FläktGroup

Model: Pi Function Modbus Communication (IQAZ-35 )

Type: Installation guide

FläktGroup Pi Function Modbus Communication (IQAZ-35 ) enables Demand Controlled Ventilation based on CO2 levels and occupancy, providing energy savings and improved indoor air quality. It integrates seamlessly with FläktGroup STRA-24 room controllers, offering various operation modes such as OFF, Standby, unoccupied, occupied, and boost.

The Pi Function maintains airflow at set points despite pressure fluctuations, ensuring optimal ventilation performance. Its pressure-independent functionality makes it suitable for any ductwork system. It offers precise airflow control with configurable parameters for non-occupancy (V0), standard occupancy (Vmin), and high occupancy (Vmax).

FläktGroup FG_DC_9703GB_20210222_R3

Specifications are subject to alteration without notice

PI FUNCTION MODBUS COMMUNICATION

CHILLED BEAMS

PI FUNCTION (OPTION)

For Demand Controlled Ventilation operation, the Pi Function accessory

must be mounted on the chilled beam. Thanks to this function, an

actuator will then change automatically the nozzle position in order to

change primary airﬂow.

The chilled beam system will be able to follow different operation se-

quences depending on the controller chosen. It is possible to set dif-

ferent airﬂows according to occupancy level or to manage air quality

thanks to a CO2 sensor connected to the controller. Three parameters

can be set in the actuator : V

for non-occupancy, V

min

for standard

occupancy and V

max

(boost) for high occupancy level.

Combined with the STRA-24 room controller, different modes are of-

fered : OFF, Standby, unoccupied, occupied and boost. For each mo-

des, different sequences between water and air are possible: cooling

without free cooling, cooling with free cooling and airﬂow depending

on CO

The Pi function keeps airﬂow at set point value despite pressure ﬂuctu-

ations in the duct. The Pi Function is easy to retroﬁt and applicable to

any ductwork system owing to its pressure independent functionality.

Note. When using Pi Function, induction is always symmetrical and a

room controller is required to operate Pi Function with link to occupan-

cy sensor. Duct pressure has to be maintained between 40 and 140 Pa.

Caution! If Pi Function is installed as a retroﬁt, there is no need for

a damper before the chilled beam. Any previously installed damper,

should be set to fully open position or removed.

Room controller signal (V)

Non-occupancy

airﬂow

Occupancy

Min. airﬂow

Vmin

(Boost mode)

Occupancy

Max. airﬂow

Vmax

Actuator

airﬂow setting

Pi-function Modbus communication

FläktGroup FG_DC_9703GB_20210222_R3

Speciﬁcations are subject of alteration without further notice

MODBUS INSTALLATION

1. Connect A and B (2 white cables).

2. Default Modbus address is 1. If you would like to change the

address, then turn right knob to address and then the actual

address is displayed on screen.

Display number EEPROM-value Baudrate Parity Stop bits

1 0 9600 none 2

2 1 9600 even 1

3 2 9600 odd 1

4 3 19200 none 2

5 4 19200 even 1

6 5 19200 odd 1

7 6 38400 none 2

8 7 38400 even 1

9 8 38400 odd 1

3. Then select address with value selector. Address ﬂashes on screen

when selected.

4. Set baudrate 19200, 8 Data bits, Parity Even, 1 stop bit.

5. If another baudrate want to be used then factory setting (19200, 8

Data bits, Parity Even, 1 sto) bit), baudrate can be selected direct on

display as described below

6. Modbus address is chosen according to description above and after

the address is conﬁrmed by 2 ﬂashing, the value selector is turned

to end stop “+”. The displays shows “2 in” which indicates the se-

cond level. At second level Baudrate can be selected according to

“display number” in table below. When value is selected, display

ﬂashing 2 times to conﬁrm the new value.

7. Baudrate can also be selected with Modbus parameter 568 with

use of same table below.

OPERATING VALUES

Name Address decimal Data Type Value range r/w Description Memory def. value

Set point 0Word 0…10000 r/w

Setpoint [%]

0…100% ’0’: set point is read only

When the override control is activated,

value in register will be -1.

Vmin = 0% Vmax 100 %

RAM

Override control 1Word 0…5 r/w

Override control

’0’ - - - ’1’ open

’2’ close ’3’ min

’4’ max ’5’ V0

RAM

Command 2Word 0…4 r/w

Command

’0’ - - - ’1’ adaption

’2’ - - - ’3’ - - -

’4’ controller reset

RAM

Device ID 3Word 0…7 r

Device ID

’0’ - - - ’1’ standard actuator

’2’ VAV ’3’ ﬁre damper

’4’ GUAC VAV ’5’ GUAC CM

’6’ GT ’7’ PICB

EEPROM 7

Relative position 4Word 0…10000 rRelative position [%]

0...100.00 RAM

Relative ﬂow 6 Word 0…10000 rFlow [%] 0…100 scaled to Vmax

100% = sqrt(150) × K100% RAM

Absolute ﬂow 7Word 0…65535 rFlow [l/s] RAM

Warning!

If the actuator is in the startup mode, all

service values cannot be changed.

When address 2 (command) changes the

operating value to '0', startup procedure is

ﬁnalized.

Pi-function Modbus communication

FläktGroup FG_DC_9703GB_20210222_R3

Speciﬁcations are subject of alteration without further notice

HOLDING REGISTER SERVICE VALUES

Name Address decimal Data Type Value range r/w Description Memory def. value

Serial number 1 100 Word 101...991 2 rserial number JJMM EEPROM

Serial number 2 101 Word 100...312 3 rserial number DDHH EEPROM

Serial number 3 102 Word 01...5959 9 rserial number MMSSXX = test number EEPROM

Software version 103 Word 1...65535 rsoftware version EEPROM

Service information 104 Word 0...65535 rsee table status-register RAM

V0 value absolute 119 Word 0...65535 r/w V0 value (m3/h)(l/s)(pa) Integer value EEPROM

min value absolute 120 Word 0...65535 r/w min value (m3/h)(l/s)(pa) Integer value EEPROM

max value absolute 121 Word 0...65535 r/w max value (m3/h)(l/s)(pa) Integer value EEPROM

Mode signal set point

analog output 122 Word 0...3 r/w

Value Referencing signal Analog out

EEPROM

0Analog in 1 Actual ﬂow (V)0..10

1Communication via

Modbus register 0 Actual ﬂow (V)0..10

2Communication via

Modbus register 0

Value written in

3Analog in 1 Value written in

Device address 130 Word 1 -247 r/w Device address 1 - 247 EEPROM

K 100% 221 Word 0..9990 r/w K 100% Value EEPROM

Attention!

Please be aware that the "EEPROM" has

limited capacity to accept changes. Excessive

alterations will result in EEPROM failure.

STATUS REGISTER ADRESS 104

Bit number Bit name Function / Status

Bit 0 bepf 1 ! eeprom error checksum 1

Bit 1 bepf 2 ! eeprom error checksum 2

Bit 2 bauf 1 Kat1 free for write

Bit 3 bauf 2 Kat2 free for write

Bit 4 bfaterr fatal EEPROM-error, device is inoperable

Bit 5 bblock ! 1 = block detected

Bit 6 bschleich 1 = seepage ﬂow detected

Bit 7 bfahrt 1 = motor drive

Bit 8 -not used

Bit 9 -not used

Bit 10 -not used

Bit 11 bMotor Timeout 1 = motor max running time expired. Motor running in one direction and does not reach an end position or dead band.

FläktGroup Pi Function Modbus Communication (IQAZ-35 ) Installation guide

FläktGroup Pi Function Modbus Communication (IQAZ-35 ) Installation guide

FläktGroup Pi Function Modbus Communication (IQAZ-35 ) Installation guide

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