RDF302, RDF302.B RDF302/VB Flush-mounted room thermostats with RS485 Modbus communications RDF302, RDF302/VB, RDF302.B Basic documentation Edition 1.
Contents 1. About this document ........................................................................... 4 1.1 Revision history ..................................................................................... 4 1.2 Reference documents ............................................................................ 5 1.3 1.3.1 1.3.2 1.3.3 Before you start ..................................................................................... 6 Copyright ..............................................
.12.1 3.12.2 Overview ............................................................................................. 44 Description of communication objects .................................................. 45 3.13 3.13.1 3.13.2 3.13.3 3.13.4 Control parameters .............................................................................. 50 Parameter setting via local HMI............................................................ 50 Parameter setting / download via Modbus communication tool ..........
1. 1.1 About this document Revision history Edition 1.5 Date 2020-12-01 Changes Update function code description Section 3.12.2 Pages 45-49 1.4 2020-02-21 Add product RDF302/VB related information 1.3 2018-12-04 Add product RDF302.B related information 1.2 1.4 1.5 2.1 2.2 2.4 3.7.1 3.11 3.12.1 4.3 6.1 1.1, 1.2 1.4, 1.5 2.1, 2.2 2.4 3.2 3.2.1 3.5 3.6.4 3.7.1 3.9 3.11, 3.11.1 3.12 3.12.2 3.13.4 4.1 4.3 5.1 6.1 7 3.12.1 3.12.2 3.2 3.2.1 3.12.2 2.5 3.4 3.6 3.7.1 4.1 4.
1.2 Reference documents Subject Modbus Manual Ref [1] RDF302, RDF302/VB, RDF302.B Room Thermostat with Modbus Interface SEZ50MB (RWD Modbus) [2] [3] [4] Doc No. Description MODBUS over serial line specification and implementation guide (http://www.modbus.
1.3 Before you start 1.3.1 Copyright This document may be duplicated and distributed only with the express permission of Siemens, and may be passed only to authorized persons or companies with the required technical knowledge. 1.3.2 Quality assurance This document was prepared with great care.
1.4 Target audience, prerequisites Product & sales managers, distributors, re-sellers & OEM customers who use RDF302, RDF302/VB and RDF302.B room thermostats in the RS485 Modbus RTU network. Since Modbus protocol has been well known for years in the industry, this document will explain the operations related to RDF302, RDF302/VB and RDF302.B Modbus units. e.g. the unit setup, available settings and their applications.
2. 2.1 Summary Types Product no. Stock no. Operating voltage RDF302 RDF302/VB RDF302.B S55770-T238 S55770-T428 S55770-T416 AC 230 V AC 230 V AC 230 V Control outputs 3-pos 1 1) 1 1) 1 1) ON/OFF 2 1) 2 1) 2 1) Suitable conduit box Color square square square White Black White 1) Selectable: ON/OFF or 3-position 2.2 Ordering Product no. RDF302 RDF302.B RDF302/VB Stock no.
2.
Functions · Room temperature control via built-in temperature sensor or external room temperature / return air temperature sensor · Changeover between heating and cooling mode (automatic via local sensor or Modbus, or manually) · Selection of applications via DIP switches or commissioning tool.
2.5 Equipment combinations Description Cable temperature sensor or changeover sensor cable length 2.5 m NTC (3 kW at 25 °C) Room temperature sensor NTC (3 kW at 25 °C) Cable temperature sensor cable length 4 m NTC (3 kW at 25 °C) ON / OFF actuators Product no. Data sheet QAH11.1 1840 QAA32 1747 QAP1030/UFH 1854 Condensation monitor / Dew point monitor QXA2601 / QXA2602 / QXA2603 / AQX2604 3302 Electromotoric ON / OFF actuator SFA21...
2.6 Accessories Description Product no. / SSN Changeover mounting kit (50 pcs / package) Plastic mounting spacer for flush mount thermostats to increase the headroom in the conduit box by 10 mm ARG86.3 Data sheet N3009 ARG70.
3. 3.1 Functions Temperature control General note: Parameters Setting of the control parameters (P01, etc., mentioned throughout the document) is described in section 3.13. Temperature control The thermostat acquires the room temperature via built-in sensor, external room temperature sensor (QAA32), or external return air temperature sensor (QAH11.1), and maintains the setpoint by delivering actuator control commands to heating and/or cooling equipment.
3.2 Operating modes The thermostat's operating mode can be influenced in different ways. e.g. operating mode button, switch over contact, Modbus, etc. Specific heating and cooling setpoints are assigned to each operating mode. Room operating mode: Preselection The operating mode can be selected via Modbus. · If a bus command is received via MODBUS for either COMFORT or ECONOMY operating mode, the symbol of the selected operating mode will be displayed. i.e.
3.2.1 Priority of operating mode interventions Different ways to influence the operating mode The operating mode can be influenced by different interventions. The table below shows the priorities of different interventions. (i.e. lower number higher priority) Priority Description Commissioning Availability of Economy mode Remark In parameter setting mode (highest priority), you can always command an operating mode independent of all other settings or intervention via Modbus and local input.
Operating mode switchover contact (window contact) The thermostat can be forced into Economy mode (e.g. when a window is opened, when a presence detector signals "no one present", when the keycard of a hotel room is withdrawn, etc). The contact can be connected to multifunctional input X1, X2. Set parameter P38, P40 to 3. The function is also available via the Modbus signal "Window state", Room operating mode: Window State Note: Only one input source must be used, either local input X1/X2 or Modbus.
3.3 Room temperature setpoint 3.3.1 Comfort mode Description The factory setting for the Comfort basic setpoint is 21 °C and can be changed in the thermostat’s EEPROM via parameter P08 or via Modbus with communication object "Comfort basic setpoint". The last intervention always wins. The Comfort setpoint can be adjusted via the +/- buttons, or via Modbus from a remote device like a touch panel or master unit, etc. The last intervention always wins.
Caution If a setpoint (Economy or Protection) is set to OFF, the thermostat does not control the room temperature in the corresponding mode (heating or cooling). This means no protective heating or cooling function and thus risk of frost in heating mode or risk of over-temperature in cooling mode! The Economy setpoints are accessible at the service level (P11, P12); the Protection setpoints at the expert level (P65, P66). 3.3.
General notes: · Changes via the local HMI or via tool have the same priority (last always wins) · Setting the Comfort basic setpoint will reset the runtime Comfort setpoint to the basic setpoint Notes on setpoint adjustment · The resulting (current) setpoint heating and cooling is limited by the Protection setpoint; if Protection setpoint is OFF, then minimum 5 °C and maximum 40 °C are used · The resulting setpoints for cooling and heating of the same operating mode have a minimum distance of 0.
3.4.
Applications for universal systems *) 3.4.
3.4.
3.5 Heating / cooling changeover via Modbus Heating/cooling changeover Automatic heating / cooling changeover via changeover sensor Additional functions The heating / cooling changeover information can be received via Modbus. This is only possible if the control sequence is set to automatic heating / cooling changeover (parameter P01 = 3) and no local input X1, X2 is assigned with this function. Note: RDF302.B does not have inputs X1 and X2. In the absence of the required information (e.g.
External / return air temperature sensor The thermostat acquires the room temperature via built-in sensor, external room temperature sensor (QAA32), or external return air temperature sensor (QAH11.1) connected to multifunctional input X1 or X2. Inputs X1 or X2 must be commissioned accordingly. See section 3.9 “Multifunctional input”. Purge function The changeover sensor ensures changeover from heating to cooling mode based on the acquired water temperature.
The table below shows the relation between parameter, temperature source and temperature display: Parameter P51 External temp. sensor available Source for display of room temperature Output control according to OFF OFF 10...50 ˚C No Yes No Built-in sensor External temp. sensor Built-in sensor 10…50 ˚C Yes Built-in sensor Built-in sensor External temp. sensor Built-in sensor Built-in sensor + limit by external sensor Floor temp.
3.6 Control sequences 3.6.1 Sequences overview (setting via parameter P01) The main control sequence (i.e. the water coil sequence of the fan coil unit) can be set via parameter P01. The following sequences can be activated in the thermostats (each without or with auxiliary heating). The available sequences depend on the application (selected via DIP switch, see section 3.4).
3.6.2 2-pipe fan coil unit On 2-pipe applications, the thermostat controls a valve in heating / cooling mode with changeover (automatically or manually), heating only, or cooling only. Cooling only is factory-set (P01 = 1). ON/OFF control The diagrams below show the control sequence for 2-position control.
3.6.3 2-pipe fan coil unit with electric heater Heating or cooling with auxiliary heater On 2-pipe applications with electric heater, the thermostat controls a valve in heating / cooling mode with changeover, heating only, or cooling only plus an electric heater. Cooling only is factory-set (P01 = 1) with enabled electric heater (P13). Electric heating, active in cooling mode In cooling mode, the valve receives an OPEN command if the acquired temperature is above the setpoint.
ON/OFF control The diagrams below show the control sequence for 2-position. Heating mode Cooling mode (automatic changeover = heating or heating only) (man. / auto.
3.6.4 4-pipe fan coil unit On 4-pipe applications, the thermostat controls 2 valves in heating and cooling mode, heating / cooling mode by manual selection, or heating and cooling mode with changeover. Heating and cooling mode (P01 = 4) is factory-set. 4-pipe application with manual changeover The heating or cooling output can be released via operating mode button if parameter P01 is set to Manual (P01 = 2).
The diagrams below show the control sequence for 2-position control.
3.6.5 Chilled / heated ceiling and radiator applications For chilled / heated ceiling and radiator, · set the corresponding basic application · disable the fan (P52) The following applications are available: Application for chilled / heated ceiling, radiator Chilled / heated ceiling with changeover Chilled / heated ceiling & el heater (cooling only: disable el heater via P13) Chilled ceiling and radiator 3.6.6 Set basic application 2-pipe See section 3.6.2 2-pipe and electric heater 3.6.3 4-pipe 3.
3.6.7 2-pipe applications Setpoints and sequences On changeover applications, the Comfort setpoints for heating and cooling sequence are the same (w). On 2-pipe applications with electric heater, the Comfort setpoint is either at the first heating sequence (in heating mode) or at the cooling sequence (in cooling mode). The setpoints for Economy and Protection mode are below the Comfort setpoints (heating) and above the Comfort setpoints (cooling).
On 4-pipe applications, the Comfort setpoint (w) is in the middle of the dead zone, between the heating and cooling sequence. 4-pipe applications The dead zone can be adjusted via parameter P33. If manual changeover is selected, then either the cooling sequence or the heating sequence is released. In this case, the Comfort setpoint is at the selected heating or cooling sequence.
3.7 Control outputs 3.7.1 Overview of control outputs Overview Different control output signals are available. They need to be defined during commissioning (see below). Control output 2-position Product no. RDF302, RDF302/VB, RDF302.B *) Only on 2-pipe application ON/OFF control signal (2-position) Y11, Y21 (2 x SPST) 3-position Y11, Y21 *) (1 x / ) The valve or compressor receives the OPEN/ON command via control output Y11 or Y21 when… 1.
Synchronization 1. When the thermostat is powered up, a closing command for the actuator running time + 150% is provided to ensure that the actuator fully closes and synchronizes to the control algorithm. 2. When the thermostat calculates the positions "fully close" or "fully open", the actuator's running time is extended + 150% to ensure the right actuator position is synchronized to the control algorithm. 3.
3.8 Fan control The fan operates in automatic mode or at the selected speed with manual mode. In automatic mode, the fan speed depends on the setpoint and the current room temperature. When the room temperature reaches the setpoint, the control valve closes and the fan switches off or stays at fan speed 1 (parameter P60; factory setting: 0 = fan speed 1 in dead zone). Only one fan output at a time is on, either Q1, Q2 or Q3. The fan speed and mode can be changed via Modbus.
1-speed / 3-speed fan The thermostat can control a 1- or 3-speed fan (selected via control parameter P53). A 1-speed fan is connected to terminal Q1, a 3-speed fan to terminals Q1, Q2 and Q3. Fan operation as per heating / cooling mode, or disabled Fan operation can be limited to be active with cooling only or heating only, or even be totally disabled via control parameter “Fan control” P52.
Fan overrun for electric heater Fan failure Clean fan filter reminder When the electric heater is switched off, the fan overruns for 60 seconds (parameter P54) to avoid over-temperature of the electric heater or prevent the thermal cutout from responding. In case of fan failure, the thermostat cannot protect the electric heater against over-temperature. For this reason, the electric heater must feature a separate safety device (thermal cutout).
3.9 Multifunctional input, digital input The thermostat has 2 multifunctional inputs X1 and X2. RDF302.B does not have inputs X1 and X2. An NTC type sensor like the QAH11.1 (AI, analog input) or a switch (DI, digital input) can be connected to the input terminals. The functionality of the inputs can be configured via parameters P38 + P39 for X1 and P40 + P41 for X2. X1 input X2 input The current temperature or state of the inputs X1/X2 is available on Modbus for monitoring purposes.
# Function of input Description 5 Enable electric heater Digital input to enable / disable the electric heater via remote control. Type X1/X2 DI Enable electric heater Enable electric heater is also possible via Modbus. In this case, the function must not be assigned to any local input X1, X2. See also section 3.6. 6 Fault Digital input to signal an external fault (example: dirty air filter). If the input is active, “ALx” is displayed and a fault is sent on the Modbus. See also section 3.11.1.
3.10 Handling faults Temperature out of range When the room temperature is outside the measuring range, i.e. above 49 °C or below 0 °C, the limiting temperatures blink, e.g. “0 °C” or “49 °C”. In addition, the heating output is activated if the current setpoint is not set to “OFF”, the thermostat is in heating mode and the temperature is below 0 °C. For all other cases, no output is activated. The thermostat resumes Comfort mode after the temperature returns to within the measuring range.
3.11 Modbus RTU mode The RDF302, RDF302/VB and RDF302.B thermostats support communication protocol (Modbus RTU mode) as per the Modbus specification (refer to: http://www.modbus.org). Device address The device address range is from 1 to 247. The device address can be changed via parameter P81. (factory setting = 1) Baud rate The available baud rates are 4800 bps, 9600 bps, 19200bps and 38400 bps. The baud rate can be changed via parameter P68.
3.12 Communication objects 3.12.
3.12.2 Description of communication objects System time 0x10 1001 1 RO 0x04 - 1 - Comfort 0 Default Data Type (Decimal) 0x03 Special Process R/W MutiBytes Access Group 4 0600… Functioncode(HEX) 0x03---Read Holding Registers 0x04---Read Input Registers 0x06---Write Single Register 0x10---Write Multiple Registers Read Only (RO) or Read/Write (R/W) Object Write Register Length 1 Address (Decimal) Object No.
Data Type (Decimal) Default Special Process MutiBytes Access Group Write Functioncode(HEX) 0x03---Read Holding Registers 0x04---Read Input Registers 0x06---Write Single Register 0x10---Write Multiple Registers Read Only (RO) or Read/Write (R/W) Register Length Object Address (Decimal) Object No. Read 100 = High Fan 17 Room 0103 1 R/W 0x03 0x06 2 x50 5 ...
Functioncode(HEX) 0x03---Read Holding Registers 0x04---Read Input Registers 0x06---Write Single Register 0x10---Write Multiple Registers MutiBytes Access Group Special Process P06 0006 1 R/W 0x03 0x06 3 - 0 33 P07 0007 1 R/W 0x03 0x06 3 - 0 34 P08 0008 1 R/W 0x03 0x06 3 x50 21 °C 5 ... 40 °C 35 P09 0009 1 R/W 0x03 0x06 3 x50 5 °C 5 ...
Functioncode(HEX) 0x03---Read Holding Registers 0x04---Read Input Registers 0x06---Write Single Register 0x10---Write Multiple Registers MutiBytes Access Group Special Process P49 0049 1 R/W 0x03 0x06 6 - 1 min. 55 P50 0050 1 R/W 0x03 0x06 6 - OFF 56 P51 0051 1 R/W 0x03 0x06 6 x50 OFF 57 P52 0052 1 R/W 0x03 0x06 6 - 1 58 P53 0053 1 R/W 0x03 0x06 6 - 3-speed 59 P54 0054 1 R/W 0x03 0x06 6 - 60 sec 1...
System clock format 8 octets Format: 8MSB 7 6 5 4 YYYYYYYY 0000 MMMM 000 DDDDD ddd hhhhh 00 mmmmmm 3 2 00 ssssss Encoding: See below Range: See below Unit: See below 1LSB F, WD, NWD, NY, ND, NDoW, NT, SUTI CLQ,0000000 Datapoint Type ID: Name: 19.
3.13 Control parameters A number of control parameters can be readjusted to optimize control performance. This can be done on the thermostat via HMI or via commissioning / operating tool. These parameters can also be set during operation without opening the unit. In the event of a power failure, all control parameter settings are retained.
Parameter 3.13.3 Parameters of the “Service level” Name Factory setting Service level 4-pipe: [2…4] 4 (Heating & Cooling) 0 = Heating only 1 = Cooling only 2 = Manual Heating or Cooling 3 = Auto Changeover 4 = Heating & cooling P02 Mode selection by user via operating mode button 1 (Comfort, Protection) 1 = Comfort, Protection 2 = Comfort, Economy, Protection P04 Selection of °C or °F °C 0 = °C 1 = °F P05 Sensor calibration (build in sensor only) 0.
Parameter 3.13.4 Parameters of the "Expert level with diagnostics and test" P30 P31 P33 P34 P35** P36** P37** P38**** P39**** P40**** P41**** P44*** P46 Name Factory setting Range 2K 0.5 … 6 K 1K 2K 2K 5 min 0.5 … 6 K 0.5 … 5 K 0.5 … 5 K 0…10 min 16 °C 10…25 °C 28 °C 27…40 °C 0 = --- (no function) 1 = Room temp ext.
Parameter Name Factory setting Range Off, 100…9900 hrs OFF, 5…WCoolProt; WCoolProt = 40 °C max OFF, WHeatProt… 40; WHeatProt = 5°C min 0 = 4800 BPS 1 = 9600 BPS 2 = 19200 BPS 3 = 38400 BPS OFF = Disabled ON = Enabled 0 = Odd Expert level P62 P65 Service filter Protection heating setpoint Off (0) 8 °C P66 Protection cooling setpoint OFF P68 Baud Rate 2 P69 Temporary Comfort setpoint OFF P70 Parity 1 1 = Even Note: P71 Restore factory setting OFF P81 Device address 1 2 = No parity
4. 4.1 Handling Mounting and installation Mount the room thermostat on a recessed square conduit box with 60.3 mm fixing centers. Do not mount on a wall in niches or bookshelves, behind curtains, above or near heat sources, or exposed to direct solar radiation. Mount about 1.5 m above the floor.
4.2 Commissioning The room thermostats are delivered with a fixed set of applications. Applications Select and activate the relevant application during commissioning using one of the following tools: – Local DIP switch and HMI – commissioning tools for RS485 Modbus RTU DIP switches Set the DIP switches before snapping the front panel to the mounting plate, if you want to select an application via DIP switches.
4.3 Operation See also Operating Instructions B3171 [2] enclosed with the thermostat. Layout 1 2 3 RDF302, RDF302/VB, RDF302.
Display 1 5 2 6 3 7 5 8 4 1 Operating mode Protection Comfort Economy 2 Displays room temperature, 6 setpoints and control parameters Symbol indicates current room temperature 7 3 Fan mode Auto fan active Fan speed low, medium, high 4 5 8 Heating/cooling mode Cooling Heating Electrical heater active Condensation in room (dew point sensor active) Additional user information, like outdoor temperature ( ) or time from Modbus (selectable via parameters) Key lock active Indicates fault or reminder
5. 5.1 Connection Connection terminals L, N Q1 Q2 Q3 Y11,Y21 Operating voltage AC 230 V Control output “Fan speed 1 AC 230 V” Control output “Fan speed 2 AC 230 V” Control output “Fan speed 3 AC 230 V” Control output “Valve” AC 230 V (N.O., for normally closed valves), output for compressor or output for electrical heater 1) X1, X2 Multifunctional input for temperature sensor (e.g. QAH11.
5.2 L AC 230 V 10 A 2-pipe / heating or cooling – ON/OFF L S1 S2 B1 B2 X1 M Y11 N Q1 Q2 Q3 1-stage compressor – C1 = Heating and / or – C2 = Cooling 1-stage compressor and electric heater Y21 N1 V1 M1 5(2)A Max. 5(2)A Max . 2-pipe, / heating or cooling – 3-position – Y11 = Open – Y21 = Close 4-pipe / Heating and radiator – V1 = Heating – V2 = Cooling + X2 I II III N 2-pipe and el. heater/ Heating or cooling and el.
6. 6.1 Mechanical design General The thermostats consist of 2 parts: · Front panel with electronics, operating elements and built-in room temperature sensor. · Mounting base with power electronics. The rear of the mounting base contains the screw terminals. The base fits on a square conduit box with 60.3 mm fixing centers. Slide the front panel in the mounting base and snap on. Operation and settings 1 2 3 RDF302, RDF302/VB, RDF302.B 1. Operating mode selector 2. Change fan operation 3.
6.
7. Power supply Caution Outputs AC 230 V 5 mA…5(2) A Fans must NOT be connected in parallel! Note! Connect one fan directly, for additional fans, one relay for each speed. Caution Modbus Rated voltage AC 230 V Overvoltage category III Frequency 50/60 Hz Power consumption Max. 7VA / 3.7 W No internal fuse! External preliminary protection with max C 10 A circuit breaker required in all cases. Fan control Q1, Q2, Q3-N Rating STOP Inputs Technical data Control output Y11-N / Y21-N (N.O.
Operational data Switching differential, adjustable Heating mode (P30) Cooling mode (P31) Setpoint setting and range Comfort (P08) Economy (P11-P12) Protection (P11-P12) Multifunctional input X1/X2 **) Input X1 default value (P38) Input X2 default value (P40) Built-in room temperature sensor Measuring range Accuracy at 25 °C Temperature calibration range Settings and display resolution Setpoints Current temperature value displayed Storage Climatic conditions Transport Climatic conditions Operation Climatic
Index Floor temperature limitation function ....................24 1 1-speed fan ........................................................ 38 3 3-position control signal ...................................... 35 3-speed fan ........................................................ 38 A Applications overview ......................................... 19 Automatic heating / cooling changeover ........ 23, 26 Automatic heating / cooling changeover via bus .. 23 B Basic application ................................
T Temperature out of range .................................... 42 Temporary setpoint ............................................. 17 W Window contact ................................................. 16 Window state................................................. 14, 40 U Universal applications .........................................
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