DeltaOHM HD402TR Series Manual 

24 • Sensor with high accuracy and stability • Measurement of pressures relative to the atmosphere or differential pressures • Dual analog output, current (active or passive) and voltage, or RS485 Modbus-RTU output • Versions with or without LCD display Applications • Control of air conditioning and ventilation • Control of filters • Monitoring of clean rooms • Pneumatic controls • Respirators • Vaporizers Description The series of transmitters HD402xT... is suitable for measuring relative pressure with respect to atmosphere or differential pressure in the range from as low as 0-50 Pa to 0-200 kPa. These transmitters use a silicon piezoresistive sensor with high accuracy and temperature compensation, which has excellent linearity, repeatability and stability over the time. The output signal of the sensor is converted, depending on the model, into a: • RS485 Modbus–RTU digital output (HD402ST); • voltage 0...10 V or active current 0...20 mA / 4...20 mA analog output (HD402T); • 2-wire (current loop) 4...20 mA analog output (HD402AT). The output signal can be transmitted over long distances with high immunity to interference (in the models with analog output the maximum distance depends on the load and the section of the connection cables, but distances of several hundred meters are commonly reached). Different units of measurement can be chosen for each model and, in the models with analog output, it is possible to choose the full scale (f.s.) value for the output (high, intermediate or low range) and set the unipolar (0 ... +f.s.) or bipolar (-f.s. ... +f.s.) measuring range. The configuration can be made through a series of dip switches mounted on the circuit board or by connecting the serial port of the transmitter to the PC. Thanks to the particular sensor used, the transmitters are insensitive to orientation and position. Moreover, the high stability of the sensor over the time and in comparison to the changes in temperature allows to eliminate the operations of maintenance typically required to compensate for the aging and the deviation of the sensor zero. The option “display” (L) is available, in this case the values of pressure are displayed on a 4 digit display under the unit of measure set by the user. The transmitters are supplied ready for use and factory calibrated in 3 points. Power supply: 24Vac or 18...40 Vdc for the models with voltage and active current analog output, 12...30 Vdc for the models with passive current analog output and for the models with RS485 Modbus RTU output. Technical specifications Sensor Piezoresistive, High stability Measuring range from 0…50 Pa to 0…200 kPa both relative and differential (please refer to table 1) Resolution Please refer to table 2 Accuracy @ 25 °C ± 1.5% f.s. nominal for HD402xT1 ± 0.75% f.s. nominal for HD402xT2 ± 1% f.s. nominal for HD402xT3, HD402xT4 and HD402xT5 Accuracy @ 0…50 °C ± 3% f.s. nominal for HD402xT1 ± 1% f.s. nominal for HD402xT2, HD402xT3, HD402xT4 and HD402xT5 Long term stability (1000 h) @ 25 °C ± 0.5% f.s. nominal for HD402xT1 and HD402xT2 ± 0.35% f.s. nominal for HD402xT3 ± 0.25% f.s. nominal for HD402xT4 and HD402xT5 Output • HD402T…: Active analog 0…10 Vdc (RLmin = 10 kΩ)) or 0…20 or 4…20 mA (RLmax = 500 Ω) • HD402AT…: 2-wire (current loop) 4…20 mA (RLmax = (Vdc-12)/0,022) • HD402ST…: Digital RS485 Modbus RTU Response time Configurable 0.125, 1, 2 or 4 seconds for the output 0.5 seconds for the display updating Overpressure limit 50 kPa for the models with f.s. up to 10 kPa 200 kPa for the model with f.s. 100 kPa 400 kPa for the model with f.s. 200 kPa Compatible media Only air and non-aggressive dry gases Power supply HD402T…: 24 Vac ± 10% or 18…40 Vdc HD402AT, HD402ST…: 12…30 Vdc Absorption HD402T… and HD402AT…: < 1 W @ 24 Vdc HD402ST…: < 100 mW @ 12 Vdc Pressure connection Ø 6.2 mm for tubes with internal Ø 5...6 mm Electrical connections Screw terminal block, max 1.5 mm2 , PG9 cable gland for the input cable Operating conditions -10...+60 °C / 0…95% RH Storage temperature -20...+70 °C Housing dimensions 80 x 84 x 44 mm Protection degree IP65 HD402T HD402ST HD402AT PRESSURE TRANSMITTERS

Model Pa kPa mbar mmH2O inchH2O mmHg PSI HD402T1 50/100/250 --- 0,5/1/2,5 5/10/25 0,2/0,4/1 --- --- HD402T2 250/500/1000 --- 2,5/5/10 25/50/100 1/2/4 --- --- HD402T3 --- 2,5/5/10 25/50/100 --- --- 10/25/50 0,4/0,75/1,5 HD402T4 --- 25/50/100 250/500/1000 --- --- 100/250/500 4/7,5/15 HD402T5 --- 50/100/200 500/1000/2000 --- --- 250/500/1000 10/15/30 TAB. 2: resolution Model Pa kPa mbar mmH2O inchH2O mmHg PSI HD402T1 0.1 --- 0.001 0.01 0.001 --- --- HD402T2 1 --- 0.01 0.1 0.01 --- --- HD402T3 --- 0.01 0.1 --- --- 0.01 0.001 HD402T4 --- 0.1 1 --- --- 0.1 0.01 HD402T5 --- 0.1 1 --- --- 1 0.01 Fig. 1: dimensions (mm) Installation In any model the sensor and the electronics are housed in a rugged plastic case with IP65 protection degree. By opening the lid, 3 mm diameter holes are available so to allow securing the base of the transmitter directly to a panel or to the wall. 65 50 Ø 3 Ø 3 Fig. 2: fixing holes (dimensions in mm) The transmitter can be mounted in any position, but typically it is secured on a vertical wall with the pressure taps facedown. The deviation of the zero due to the mounting position can be corrected by using CAL ZERO. The procedure for the manual calibration of the zero is the following: • make sure that the transmitter is powered at least for 1 hour; • disconnect both the tubes from the pressure + and – inputs; • press CAL ZERO until the red LED starts flashing; • when the red LED turns off, the zeroing procedure is completed and you can reconnect the tube to the pressure connections. It is recommended to follow the auto‑zero procedure at least once a year under normal operating conditions. CAL ZERO LED COM AUX 1 2 3 4 5 6 ON DIP SWITCH 1 2 3 4 5 6 Models with active analog output Models with RS485 output Model with 2-wire current output Fig. 3: CAL ZERO button and configuration dip-switches

Dip switch number 6 2 3 4 5 4 5 4 5 4 5 OFF OFF ON OFF OFF ON ON ON Pa mmH2O inchH2O mbar OFF OFF ON 0…50.0 Pa 0…5.00 mmH2O 0…0.200 inchH2O 0…0.500 mbar ON OFF 0…100.0 Pa 0…10.00 mmH2O 0…0.400 inchH2O 0…1.000 mbar OFF OFF 0…250.0 Pa 0…25.00 mmH2O 0…1.000 inchH2O 0…2.500 mbar ON ON ON OFF ON -50.0…+50.0 Pa -5.00…+5.00 mmH2O -0.200…+0.200 inchH2O -0.500…+0.500 mbar ON OFF -100.0…+100.0 Pa -10.00…+10.00 mmH2O -0.400…+0.400 inchH2O -1.000…+1.000 mbar OFF OFF -250.0…+250.0 Pa -25.00…+25.00 mmH2O -1.000…+1.000 inchH2O -2.500…+2.500 mbar ON ON TAB. 4: measuring ranges for outputs of the models HD402T2 and HD402AT2 Dip switch number 6 2 3 4 5 4 5 4 5 4 5 OFF OFF ON OFF OFF ON ON ON Pa mmH2O inchH2O mbar OFF OFF ON 0…250 Pa 0…25.0 mmH2O 0…1.00 inchH2O 0…2.50 mbar ON OFF 0…500 Pa 0…50.0 mmH2O 0…2.00 inchH2O 0…5.00 mbar OFF OFF 0…1000 Pa 0…100.0 mmH2O 0…4.00 inchH2O 0…10.00 mbar ON ON ON OFF ON -250…+250 Pa -25.0…+25.0 mmH2O -1.00…+1.00 inchH2O -2.50…+2.50 mbar ON OFF -500…+500 Pa -50.0…+50.0 mmH2O -2.00…+2.00 inchH2O -5.00…+5.00 mbar OFF OFF -1000…+1000 Pa -100.0…+100.0 mmH2O -4.00…+4.00 inchH2O -10.00…+10.00 mbar ON ON ON ON TAB. 5: measuring ranges for outputs of the models HD402T3 and HD402AT3 Dip switch number 6 2 3 4 5 4 5 4 5 4 5 OFF OFF ON OFF OFF ON ON ON kPa mmHg PSI mbar OFF OFF ON 0…2.50 kPa 0…10.00 mmHg 0…0.400 PSI 0…25.0 mbar ON OFF 0…5.00 kPa 0…25.00 mmHg 0…0.750 PSI 0…50.0 mbar OFF OFF 0…10.00 kPa 0…50.00 mmHg 0…1.500 PSI 0…100.0 mbar ON ON ON OFF ON -2.50…+2.50 kPa -10.00…+10.00 mmHg -0.400…+0.400 PSI -25.0…+25.0 mbar ON OFF -5.00…+5.00 kPa -25.00…+25.00 mmHg -0.750…+0.750 PSI -50.0…+50.0 mbar OFF OFF -10.00…+10.00 kPa -50.00…+50.00 mmHg -1.500…+1.500 PSI -100.0…+100.0 mbar ON ON ON ON TAB. 6: measuring ranges for outputs of the models HD402T4 and HD402AT4 Dip switch number 6 2 3 4 5 4 5 4 5 4 5 OFF OFF ON OFF OFF ON ON ON kPa mmHg PSI mbar OFF OFF ON 0…25.0 kPa 0…100.0 mmHg 0…4.00 PSI 0…250 mbar ON OFF 0…50.0 kPa 0…250.0 mmHg 0…7.50 PSI 0…500 mbar OFF OFF 0…100.0 kPa 0…500.0 mmHg 0…15.00 PSI 0…1000 mbar ON ON ON OFF ON -25.0…+25.0 kPa -100.0…+100.0 mmHg -4.00…+4.00 PSI -250…+250 mbar ON OFF -50.0…+50.0 kPa -250.0…+250.0 mmHg -7.50…+7.50 PSI -500…+500 mbar OFF OFF -100.0…+100.0 kPa -500.0…+500.0 mmHg -15.00…+15.00 PSI -1000…+1000 mbar ON ON ON ON TAB. 7: measuring ranges for outputs of the models HD402T5 and HD402AT5 Dip switch number 6 2 3 4 5 4 5 4 5 4 5 OFF OFF ON OFF OFF ON ON ON kPa mmHg PSI mbar OFF OFF ON 0…50.0 kPa 0…250 mmHg 0…10.00 PSI 0…500 mbar ON OFF 0…100.0 kPa 0…500 mmHg 0…15.00 PSI 0…1000 mbar OFF OFF 0…200.0 kPa 0…1000 mmHg 0…30.00 PSI 0…2000 mbar ON ON ON OFF ON -50.0…+50.0 kPa -250…+250 mmHg -10.00…+10.00 PSI -500…+500 mbar ON OFF -100.0…+100.0 kPa -500…+500 mmHg -15.00…+15.00 PSI -1000…+1000 mbar OFF OFF -200.0…+200.0 kPa -1000…+1000 mmHg -30.00…+30.00 PSI -2000…+2000 mbar ON ON ON ON

Fig. 5: voltage analog output Fig. 6: 2-wire current analog output Fig. 7: RS485 connection In the RS485 connection, the instruments are connected in a sequence through a shielded cable with twisted pair for signals and a third wire for the common. Line termination must be set at the two network ends. The maximum number of devices that can be connected to the RS485 line (Bus) depends on the load characteristics of the devices to be connected. The RS485 standard requires that the total load does not exceed 32 unit loads. The load of an HD402ST… transmitter is equal to ¼ of unit load. If the total load is greater than 32 unit loads, divide the network into segments and add a signal repeater between a segment and the successive one. Line termination should be applied at both ends of each segment. The instrument has a built in line termination that can be connected or removed through a short jumper placed next to the terminal block. If the instrument is the last or the first device of a network group, connect the termination placing the short jumper between the “RT” and “120 ohm” indications. If the instrument is not at the end of a network group, remove the termination placing the short jumper between the “RT” and “OPEN” indications. The cable shield must be connected to both line ends. The cable should have the following features: • Characteristic impedance: 120 ohm • Capacity: less than 50pF/m • Resistance: less than 100 ohm/km • Gauge: 0,22 mm2 (AWG24) at least The cable maximum length depends on baud rate and cable characteristics. Typically, the maximum length is 1200 m. The data line must be kept separated from any power lines in order to prevent interferences on the transmitted signal. +Vcc +Vcc Iout Iout Vout Current output Voltage output Vout GND GND 24 Vac 18...40 Vdc 24 Vac 18...40 Vdc + + - - I 0/4...20 mA OUT + - R L + - V 0...10 V OUT Powe supply Termination Termination Other sensors with RS485 output PLC, data logger or RS485/USB or RS485/ RS232 converter for PC CONFIGURATION OF THE MODELS WITH ANALOG OUTPUT (HD402T... / HD402AT…) Setting the configuration mode: the transmitter can be configured by using the dip switches on the circuit board or via the serial communication port COM AUX. The choice of the configuration mode is done with the dip switch 1: 1 2 3 4 5 6 ON 1 2 3 4 5 6 ON OFF Dip switch 1 = ON → the configuration set through the dip switches 2...6 is used Dip switch 1 = OFF → the configuration set via serial port is used Configuration by dip switch (models with analog output) The configuration of the dip switches is used by the transmitter only if the dip switch 1 is ON. The dip switches 2 and 3 select the low, intermediate or high measuring range for the analog output. The dip switches 4 and 5 select one of the four available units in the model. The dip switch 6 sets the unipolar (0 ... + f.s.) or bipolar (-f.s.....+ f.s.) measuring range for the analog output. A dip switch is OFF when placed down, towards the serial connector. Instead, it is ON if placed up, towards the DIP SW sign. The tables 3 to 7 at the following pages report..... report the measuring range, for each model, corresponding to the analog outputs according to dip switch positions. Configuration via the serial port COM AUX (models with analog output) The configuration set with the serial communication is used by the transmitter only if the dip switch 1 is OFF. In order to modify the settings, please proceed as follows: • Connect the serial COM AUX output of the transmitter to the RS232 port (via the RS27 cable) or USB (via the cable CP27) of the PC. If you use the CP27 cable, install the USB drivers on your PC. • On the PC, launch a program for serial communication (e.g. Hyperterminal), set the baud rate to 115200 and the communication parameters to 8N1. • Send the commands given in table 8 to set the measurement range corresponding to the analog outputs. TAB. 8: configuration serial commands (models with analog output) Command Response Description Kn & Set the unit of measurement of index n HD402T1 & HD402T2 HD402T3 & HD402T4 & HD402T5 n=0 → Pa n=0 → kPa n=1→ mmH2O n=1 → mmHg n=2 → inchH2O n=2 → PSI n=3 → mbar n=3 → mbar Rn & Set the measuring range of index n n=0 → high range (e.g. 250 Pa / 25 mmH2O / 1 “H2O / 2,5 mbar in HD402T1) n=1 → intermediate range (e.g. 100 Pa / 10 mmH2O / 0,4 “H2O / 1 mbar in HD402T1) n=2 → low range (e.g. 50 Pa / 5 mmH2O / 0,2 “H2O / 0,5 mbar in HD402T1) PU & Set the unipolar measuring range (0…+f.s.) PB & Set the bipolar measuring range (-f.s.…+f.s.) Sn & Set the response time of index n for the analog outputs n=0 ⇒ 0.125 s n=1 ⇒ 1 s n=2 ⇒ 2 s n=4 ⇒ 4 s U0 & Set the interval 0…20 mA for the analog active current output U1 & Set the interval 4…20 mA for the analog active current output In order to read the settings of the transmitter, send the commands described in Table 9. +Vcc +Vcc Iout Iout Vout Uscita in corrente Uscita in tensione Vout GND GND 24 Vac 16...40 Vdc 24 Vac 16...40 Vdc + + - - I 0/4...20 mA OUT + - R L + - V 0...10 V OUT

output) Command Response Description G0 See the example below It reads the current configuration of the transmitter. If the dip switch 1 is OFF, it returns the configuration set via the serial port. If the dip switch 1 is set to ON, it returns the configuration set by dip switch GF See the example below It reads the configuration set by the serial port GS See the example below It reads the configuration set by the dip switch S? Response time It reads the response time set for the analog outputs The commands G0, GF and GS for reading the configuration return a string consisting of: • model • full scale value set for the analog outputs • polarity of the measuring range (U=unipolar, B=bipolar) • range of the analog output current (0=0...20mA, 4=4...20 mA) for example: the string “HD402T2 5.00mbar B40” indicates that the transmitter model is HD402T2, the full scale set for the analog outputs is 5.00 mbar, the measuring range is bipolar (‑5.00…+5.00 mbar) and the analog current output type is 4...20 mA. The last character of the string (0 in the example) is a confidential code. CONFIGURATION OF THE MODELS WITH RS485 MODBUS-RTU OUTPUT (HD402ST...) RS485 Modbus address: each transmitter of the network is univocally identified by an address between 1 and 247. Transmitters having the same address shall not be present in the network. The transmitter Modbus address is equal to the sum of the value set with the dip switches 2…6 (value settable from 0 to 31) and the value set with the serial command WA (value settable from 1 to 216, default = 1). By setting a dip-switch to ON (upwards), the following values are added to the address: Dip-switch 2 Dip-switch 3 Dip-switch 4 Dip-switch 5 Dip-switch 6 ON 16 8 4 2 1 OFF 0 0 0 0 0 Example: if the dip-switches 2 and 4 are set to ON, and the dip-switches 3,5 and 6 are set to OFF, the value set with the dip-switches is 16+4=20. If the value set with the serial command WA is 1 (default value), the transmitter Modbus address is 20+1=21. The dip-switches can be set even if the transmitter is powered, and the change is effective immediately. Configuration via the RS485 serial port (models HD402ST…) The transmitters are preset by the factory. To change the settings, proceed as follows: • Connect the transmitter RS485 output to the PC RS232 (through a RS485/ RS232 converter) or USB (through a RS485/USB converter, for example the RS48 cable) port. If a RS485/USB converter is used, install in the PC the related USB drivers. • To enable the configuration mode, set the dip-switch 1 (the one closest to the terminal block) to ON (upwards), then power the transmitter. Note: the dip-switch 1 can be changed from OFF to ON even when the instrument is powered; in this case it is however necessary, after setting the dip-switch to ON, to press briefly (less than 0.5 seconds) the CAL ZERO button to enable the configuration mode (the transmitter model information appears on display, if present). Alternatively, power cycle the transmitter. • In the PC, run a serial communication software (e.g. Hyperterminal), set the baud rate to 57600 and the communication parameters to 8N1. • Send the CAL START command (the command is required to change the configuratrion; to read the value of the parameters, the command is not required). • Send the commands given in table 10 to set or read the configuration parameters of the transmitter. TAB. 10: serial commands (models with RS485 Modbus RTU output) Command Description Response time AVGn Set the response time of index n for the measurement n=0 ⇒ 0.125 s, n=1 ⇒ 1 s, n=2 ⇒ 2 s, n=4 ⇒ 4 s AVG? Reads the response time set for the measurement Unit of measurement DU0 Shows pressure in Pa (HD402ST1 and HD402ST2) or kPa (HD402ST3, HD402ST4 and HD402ST5) on display DU1 Shows pressure in mmH2O (HD402ST1 and HD402ST2) or mmHg (HD402ST3, HD402ST4 and HD402ST5) on display DU2 Shows pressure in inchH2O (HD402ST1 and HD402ST2) or PSI (HD402ST3, HD402ST4 and HD402ST5) on display DU3 Shows pressure in mbar on display Modbus parameters WA n...n Sets the Modbus base address to the value n…n The value must be between 1 and 216 (default = 1) Warning: the actual Modbus address of the transmitter is equal to the base address set with this command plus the value set with the dip-switches. Note: in the reply to the command, the previous actual address appears; the new address will appear in the replies to the next commands. BAUD r...r Sets the Modbus Baud Rate to the value r…r The acceptable values are 9600 and 19200 (default = 19200) If the command is sent without the parameter r…r, the current setting is obtained PAR p Sets the Modbus communication parameters of index p p=O ⇒ 8O1 p=N ⇒ 8N2 p=E ⇒ 8E1 If the command is sent without the index p, the current setting is obtained (default = 8E1). Note: the replies of the transmitters with RS485 Modbus RTU output always start with the address of the connected transmitter. For example, sending the AVG2 command to a transmitter with Modbus address 1, the reply is “001: averaging = 2 sec”. To exit the configuration mode after sending the CAL START command, send the CAL END command (the transmitter automatically exits the configuration mode after 5 minutes from the last command sent). MODBUS-RTU MODE To operate with the Modbus-RTU protocol be sure that the dip-switch 1 (the one closest to the terminal block) is set to OFF (downwards). The dip-switch can be set to OFF even if the transmitter is powered, and the change is effective immediately. The measured values can be read in Modbus RTU mode by using the 04h function code (Read Input Registers). Table 11 lists the Modbus Input Registers available:

Register number Register address Datum Format 4 3 Pressure in tenths of Pa (only HD402ST1) 16-bit integer 5 4 Pressure in Pa (only HD402ST1, HD402ST2 and HD402ST3) 16-bit integer 6 5 Pressure in daPa (only HD402ST2, HD402ST3 and HD402ST4) 16-bit integer 7 6 Pressure in hPa (only HD402ST3, HD402ST4 and HD402ST5) 16-bit integer 8 7 Pressure in kPa (only HD402ST4 and HD402ST5) 16-bit integer 9 8 Pressure in hundredths of mmH2O (only HD402ST1 and HD402ST2) 16-bit integer 10 9 Pressure in tenths of mmH2O (only HD402ST1, HD402ST2 and HD402ST3) 16-bit integer 11 10 Pressure in mmH2O (only HD402ST2, HD402ST3 and HD402ST4) 16-bit integer 12 11 Pressure in thousandths of inchH2O (only HD402ST1 and HD402ST2) 16-bit integer 13 12 Pressure in hundredths of inchH2O (only HD402ST2 and HD402ST3) 16-bit integer 14 13 Pressure in tenths of inchH2O (only HD402ST3, HD402ST4 and HD402ST5) 16-bit integer 15 14 Pressure in inchH2O (only HD402ST4 and HD402ST5) 16-bit integer 16 15 Pressure in thousandths of mmHg (only HD402ST2) 16-bit integer 17 16 Pressure in hundredths of mmHg (only HD402ST2 and HD402ST3) 16-bit integer 18 17 Pressure in tenths of mmHg (only HD402ST3 and HD402ST4) 16-bit integer 19 18 Pressure in mmHg (only HD402ST4 and HD402ST5) 16-bit integer 20 19 Pressure in thousandths of PSI (only HD402ST3) 16-bit integer 21 20 Pressure in hundredths of PSI (only HD402ST3, HD402ST4 and HD402ST5) 16-bit integer 27 26 Error register. 16-bit integer Reading a register not available for a particular model returns the value -32768 (0x8000). Error register The bits of the error register signal, if set to 1, anomalies in the measurement. The bit 0 (the less significant one) indicates a measurement over-range of the transmitter. The bit 1 indicates whether the measurement is less than the minimum measurable (under-range). The bits 2 and 3 indicate sensor errors. TAB. 12: MODBUS - Holding Registers Register number Register address Datum Format 101 100 Modbus base address (from 1 to 216) Warning: the actual Modbus address of the transmitter is equal to the base address set in this register plus the value set with the dip-switches. 16-bit integer 102 101 Modbus Baud Rate Acceptable values: 3 (⇒ 9600) and 4 (⇒ 19200) 16-bit integer 103 102 Modbus communication para- meters Acceptable values: 1 (⇒ 8N2), 2 (⇒ 8E1) and 4 (⇒ 8O1) 16-bit integer The Modbus Holding Registers allow setting the same Modbus parameters that can be set via the serial commands WA, BAUD and PAR. Use the 06h (Write Single Register) and 03h (Read Holding Registers) function codes to write and read respectively the content of the registers. To make the changes of the Holding Registers content active and permanent, write the hexadecimal value FF00 in the Coil Register number 3 (address 2) by using the 05h function code (Write Single Coil). TAB. 13: MODBUS - Coils Register number Register address Datum 3 2 Activation and permanent storage of the Hol- ding Registers content changes. Display Models with suffix L are equipped with a 4-digit LCD display. In models with LCD option, the measuring range shown on the display is always bipolar (-f.s.....+f.s.) and related to the maximum full scale available in the model (the setting of the measuring range only affects the behavior of the analog outputs). The measure on the display is updated twice a second. Error messages: Undr → it appears if the measured value is less than the minimum measurable value OvEr → it appears if the measured value exceeds the maximum mea- surable value CAL Error → it appears at the end of the zero calibration if the maximum offset value possible to be corrected is exceeded. ORDERING CODES HD402T…: Pressure relative to the atmosphere or differential pressure transmitters. For dry air and non-aggressive gases. Barbed connection. Ø 6.2 mm for tubes with internal Ø 5...6 mm pressure inputs. RS485 Modbus RTU output (HD402ST), voltage 0...10 V or active current 0...20 mA / 4...20 mA analog output (HD402T) or 2-wire (current loop) 4...20 mA analog output (HD402AT). Operating temperature 10...+60 °C. Power supply: 24Vac or 18...40 Vdc for the models with voltage and active current analog output, 12...30 Vdc for the models with passive current analog output and for the models with RS485 Modbus RTU output. HD402 T - L L = with LCD display Nominal full scale (f.s.): 1 = 250 Pa / 25 mmH2O / 1 inchH2O / 2,5 mbar 2 = 1000 Pa / 100 mmH2O / 4 inchH2O / 10 mbar 3 = 10 kPa / 50 mmHg / 1,5 PSI / 100 mbar 4 = 100 kPa / 500 mmHg / 15 PSI / 1000 mbar 5 = 200 kPa / 1000 mmHg / 30 PSI / 2000 mbar Output: Blank = voltage and active current analog output A = 2-wire (current loop) 4…20 mA output S = RS485 Modbus-RTU output

• Measurement of pressures relative to the atmosphere or differential pressures • Relay switch output • Front alarm LED and audible alarm • Settable thresholds, hysteresis and delay • Auto-zeroing feature in the low range model • LCD display and 2 configuration keys 30 Accessories Included: •N°1 piece of silicone tubing Ø 5 int./ Ø 8 ext. length 2 m •N°2 plastic fittings HD434T.5 Upon request: AP3719: Air inlet for square or cylindrical channel. AP3721: Air inlet for cylindrical channel, made of plastic. RS27: RS232 null-modem serial connection cable with 9 poles sub-D 9 female and 3-pole connectors for COM AUX port. CP27: Serial connection cable with USB connector for PC and 3-pole connector for COM AUX port. The cable has a built-in USB/RS232 converter and connects the instrument directly to the USB port of the PC. Fig. 8: AP3719 duct probe 135 13 31 Ø 4.5 88 69 6 H FLOW L Fig. 9: AP3721 duct probe EXAMPLE OF CONNECTION WITH THE INDICATOR CONTROLLER HD9022 CAL ZERO LED COM AUX 1 2 3 4 5 6 ON DIP SWITCH 1 2 3 4 5 6 Iin GND ALARM HI LO HD9022 18...40 Vdc 24 Vac Power supply + Fig. 10: active current output 0…20 or 4…20 mA CAL ZERO LED COM AUX 1 2 3 4 5 6 ON DIP SWITCH 1 2 3 4 5 6 Vin GND ALARM HI LO HD9022 24 Vac Power supply 18...40 Vdc + Fig. 11: voltage output 0…10 Vdc Fig. 12: 2-wire (current loop) 4…20 mA output HD402TR…L series Pressure ON/OFF relay switches The series of pressure ON/OFF relay switches HD402TR...L is suitable for controlling the relative pressure with respect to atmosphere or differential pressure in the range from ±250 Pa to ±200 kPa. If the set threshold value is exceeded, the relay switch output is activated, the front alarm LED lights up and an audible alarm sounds. The alarm can be configured to be activated when the measurement becomes higher or lower than the set threshold. 1 or 2-threshold operating modes are available. A silicon piezoresistive sensor with high accuracy and temperature compensation is used, which allows excellent linearity, repeatability and stability over the time. The auto-zeroing feature in the low range model (HD402TR1L) allows stable measurements over the time without the need to recalibrate. The instruments are equipped with a 4-digit LCD display and different units of measurement can be chosen for each model. The configuration can be made through the dip switches mounted on the circuit board (only for the unit of measurement), via the internal buttons or by connecting the serial port of the instrument to the PC. Thanks to the particular sensor used, the instruments are insensitive to orientation and position. Moreover, the high stability of the sensor over the time and in comparison to the changes in temperature allows eliminating the operations of maintenance typically required to compensate for the aging and the deviation of the sensor zero. The instruments are supplied ready for use and factory calibrated. Power supply: 24Vac or 15...36 Vdc. 137 43 Ø 60 Ø42 N° 3x120° Ø5,5 3 6

Measuring range from 0…50 Pa to 0…200 kPa both relative and differential (please refer to table 1) Resolution Please refer to table 2 Accuracy @ 25 °C ± 1.5% f.s. nominal for HD402TR1L ± 0.75% f.s. nominal for HD402TR2L ± 1% f.s. nominal for HD402TR3L, HD402TR4L and HD402TR5L Accuracy @ 0…50 °C ± 3% f.s. nominal for HD402TR1L ± 1% f.s. nominal for HD402TR2L, HD402TR3L, HD402TR4L and HD402TR5L Long term stability (1000 h) @ 25 °C ± 0.5% f.s. nominal for HD402TR1L and HD402TR2L ± 0.35% f.s. nominal for HD402TR3L ± 0.25% f.s. nominal for HD402TR4L and HD402TR5L Alarm Front LED, internal buzzer, relay switch Output SPDT Relay switch 3 A/250 Vac 3 A/30 Vdc resistive load Connection to pc RS232 serial port Can be connect to a USB port by using the optional CP27 adapter Configuration Settable unit of measurement, thresholds, hysteresis, delay and alarm operation mode Auto-zero Automatic for HD402TR1L, manual for the other models Response time 0.5 seconds for the display updating Overpressure limit 50 kPa for HD402TR1L, HD402TR2L and HD402TR3L 200 kPa for HD402TR4L 400 kPa for HD402TR5L Compatible media Only air and non-aggressive dry gases Power supply 24 Vac ± 10% or 15…36 Vdc Absorption < 1 W @ 24 Vdc Pressure connection Ø 6.2 mm for tubes with internal Ø 5...6 mm Electrical connections Screw terminal block, max 1.5 mm2 , PG9 cable gland for the input cable Operating conditions -10...+60 °C / 0…95% RH Storage temperature -20...+70 °C Housing dimensions 80 x 84 x 44 mm Protection degree IP65 Model Pa kPa mbar mmH2O inchH2O mmHg PSI HD402TR1L 250 --- 2.5 25 1 --- --- HD402TR2L 1000 --- 10 100 4 --- --- HD402TR3L --- 10 100 --- --- 50 1.5 HD402TR4L --- 100 1000 --- --- 500 15 HD402TR5L --- 200 2000 --- --- 1000 30 Model Pa kPa mbar mmH2O inchH2O mmHg PSI HD402TR1L 0.1 --- 0.001 0.01 0.001 --- --- HD402TR2L 1 --- 0.01 0.1 0.01 --- --- HD402TR3L --- 0.01 0.1 --- --- 0.01 0.001 HD402TR4L --- 0.1 1 --- --- 0.1 0.01 HD402TR5L --- 0.1 1 --- --- 1 0.01 TAB. 1: full scale values and units of measurement TAB. 2: resolution Dimensions Internal view

OFF relay switch. Range from ±250 Pa to ±200 kPa depending on model. 4-digit LCD display. User configurable via serial port or internal buttons. Operating temperature 10...+60 °C. Suitable for measuring non-corrosive gases or dry air. Ø 6.2 mm for tubes with internal Ø 5...6 mm pressure inputs. Power supply 24 Vac or 15...36 Vdc. HD402TR L Range: 1 = ± 250 Pa / 25 mmH2O / 1 inchH2O / 2,5 mbar 2 = ± 1000 Pa / 100 mmH2O / 4 inchH2O / 10 mbar 3 = ± 10 kPa / 50 mmHg / 1,5 PSI / 100 mbar 4 = ± 100 kPa / 500 mmHg / 15 PSI / 1000 mbar 5 = ± 200 kPa / 1000 mmHg / 30 PSI / 2000 mbar 137 43 Ø 60 Ø42 N° 3x120° Ø5,5 3 6 135 13 31 Ø 4.5 88 69 6 H FLOW L AP3719 Flow port for for square or cylindrical duct. AP3721 Plastic flow port for cylindrical duct. RS27 RS232 null-modem serial connection cable with SubD 9-pin connector on the PC side and 3-pole connector on the instrument side. CP27 Connection cable with built-in USB/RS232 converter. USB con- nector on the PC side and 3-pole connector on the instrument side. ELECTRICAL CONNECTIONS CONFIGURATION The configuration of the instruments can be done via serial commands by connecting the instrument serial port to a PC and using a standard serial communication program, or by using the two internal configuration buttons. Below are the operating parameters that can be configured: • Relay operating mode: Negative: NC contact is closed if no alarm, NO contact is closed if in alarm. Positive: NO contact is closed if no alarm, NC contact is closed if in alarm. • Buzzer activation: ON (buzzer enabled) or OFF (buzzer disabled). • Alarm activation: ON (alarm enabled) or OFF (alarm disabled). • Alarm operating mode: Above threshold: alarm is on if measurement is greater than the set threshold. Below threshold: alarm is on if measurement is less than the set threshold. Outside thresholds: alarm is on if measurement is less than lower threshold or greater than upper threshold. • Threshold 1: Value of the threshold for above and below alarm operating modes; value of the lower threshold for outside thresholds alarm operating mode. • Threshold 2: Value of the upper threshold for outside thresholds alarm operating mode. • Hysteresis: Value of the hysteresis for above and below threshold alarm operating modes. • Alarm activation delay: Value in seconds of the time delay for generating the alarm. The alarm is generated only if the measurement exceeds the threshold for more than the set time. • Alarm deactivation delay: Value in seconds of the time delay for deactivating the alarm. The alarm is deactivated only after the set time has elapsed from the disappearance of the alarm condition.