Delta OHM BAROsense Barometric Transmitter Instruction Manual

Delta OHM BAROsense Barometric Transmitter

INTRODUCTION

BAROsense is a barometric transmitter equipped with a precision piezo- resistive pressure sensor with integrated temperature sensor. The pressure and temperature measurements are digitally processed to obtain a pressure output value compensated over the whole transmitter temperature operating range. The sensor is factory calibrated in multiple points and has excellent time stability and re-peatability. The instrument has a digital RS485 output with MODBUS-RTU or proprietary proto-col. As option, it can be supplied with an additional analog output, which can be selected by the user in current or voltage via an internal jumper. The current output is user configurable 0…20 mA or 4…20 mA (default), while the voltage output must be defined when ordering (0…1 V, 0…5 V or 0…10 V). The transmitter digital output enables the transmission of the measurements over long distances and connects the transmitter to sensors networks. The pressure can be expressed in different user-selectable units of measurement. Optional LCD display. Optional input for combined temperature and relative humidity probe. Also available with optional static port and support bracket to minimize the effect of dynamic pressure due to the wind in open field measurements.

TECHNICAL SPECIFICATIONS

Barometric pressure

Sensor| Piezoresistive
Measuring range| 300…1100 hPa

Configurable for the analog output: default 600…1100 hPa

Resolution| See table below
Accuracy| ± 0.5 hPa (700…1100 hPa) @ 20 °C

±1 hPa (500…1100 hPa) / ±1.5 hPa (300…500 hPa) @ T=(0…60 °C)

Long-term stability| < ±1 hPa/year
Relative humidity ( with optional external T/RH probe )
Sensor| Capacitive
Measuring range| 0…100%
Resolution| 0.1%
Accuracy| ± 2.5% (0..85%) / ± 3.5% (85…100%) @ T=23 °C
Temperature drift| 0.05%/K (0…60 °C)
Sensor operating temp.| -40…+105 °C (R.H. max=[100-2*(T-80)] @ T=80…105 °C)
Response time| T63 < 4 s (air speed = 2 m/s, without filter)
Long-term stability| < 1%/year (@ 23 °C and 30…70%)
Temperature ( with optional external T/RH probe )
Sensor| PTAT integrated in humidity module
Measuring range| -40…+105 °C
Resolution| 0.1 °C
Accuracy| ± 0.2 °C in the range 0…+60 °C

± (0.2 – 0.05 * T) °C in the range T=-40…0 °C

± [0.2 + 0.032 * (T-60)] °C in the range T=+60…+105 °C

Long-term stability| 0.05 °C/year
General specifications
Output| RS485 with Modbus-RTU or ASCII proprietary protocol

Optional analog output, selectable in current (0/4…20 mA) or volt- age (0…1 V, 0…5 V or 0…10 V, depending on the model)

Current output load resistance: RL < (Vdc-7)/0,022) Voltage output load resistance: RL > 10 kW

Power supply| BAROsense-M : 7…30 Vdc

BAROsense-1 and BAROsense-5 : 8…30 Vdc

BAROsense-10 : 15…30 Vdc

Consumption| 4 mA @ 24 Vdc (+ output current if current output is used)
Connection| Internal screw terminal header / PG7 cable gland for power supply and output. Optional M12 connector for the T/RH external probe.
Operating conditions| -40…+60 °C (-20…+60 °C con LCD) / 0…100%RH
Compatible media| Air and dry gases

Units of measurement available and corresponding resolution
With the MODBUS-RTU protocol, two different input registers are available for the pressure measurement, with different resolution: IR 0 (32-bit) and IR 2 (16-bit).
With the ASCII proprietary protocol, the resolution is unique.

Modbus protocol IR 2 (16-bit)

Pa| 1 Pa| 10 Pa
hPa| 0.01 hPa| 0.1 hPa
kPa| 0.001 kPa| 0.01 kPa
mbar| 0.01 mbar| 0.1 mbar
bar| 0.00001 bar| 0.0001 bar
atm| 0.00001 atm| 0.0001 atm
psi| 0.0001 psi| 0.001 psi
mmHg| 0.01 mmHg| 0.1 mmHg
inHg| 0.001 inHg| 0.01 inHg
mmH2O| 0.1 mmH2O| 1 mmH2O
inH2O| 0.01 inH2O| 0.1 inH2O
kg/cm2| 0.00001 kg/cm2| 0.0001 kg/cm2
Torr| 0.01 Torr| 0.1 Torr

INSTALLATION

The transmitter is wall mounted using the two holes on the back (open the cover to access the holes and the terminal header for electrical connections).

It is advisable to mount the transmitter so that the pressure input is facing down-wards, in order to reduce the accumulation of dust and dirt on the input. For outdoor installation, the use of the transmitter version with static pressure port (BAROsense…K) is recommended, in order to minimize the measurement error caused by the wind flow on the pressure input (the measurement deviation due to wind is less than 0.3 hPa @ 20 m/s if the static port is used). The transmitter version with static port includes a support bracket suitable for fixing to a Ø30…50 mm mast

ELECTRICAL CONNECTIONS

The transmitter has an internal screw terminal header.

internal terminal header and selection jumpers

The analog output, if present, can be in current or voltage, configurable via the jump-er to the right of the terminal header.

analog output connection
To the left of the terminal header there is a built-in line termination that can be con-nected or removed through a short jumper. To connect the termination, place the short jumper between the “RT” and “CLOSE” indications. To remove the termination, place the short jumper between the “RT” and “OPEN” indications.

CONFIGURATION AND MEASUREMENT

The configuration of the instrument and the reading of the measurements can be done via the RS485 serial output, both with the proprietary protocol and with the MODBUS-RTU protocol.
In the first 10 seconds after the instrument power on, it is always active the proprie-tary protocol. After 10 seconds from power on, the operating protocol is activated, which by default is theMODBUS-RTU protocol. It is possible to keep the proprietary protocol active even after 10 seconds from power on by sending, before the 10 seconds expire, the command @ of the proprietary protocol. The proprietary protocol can be set as operating protocol by means of the DP0 command. By default, the instrument has MODBUS address 1 and communication parameters 19200, 8E1. Different parameters can be set using the proprietary protocol or the MODBUS-RTU protocol. The commands of the proprietary protocol and the registers of the MODBUS-RTU pro-tocol are described in detail in the following chapters.

Analog output:
The output is current or voltage depending on the configuration of the IOUT / VOUT jumper on the board. By default, the current output is 4…20 mA and the voltage out-put is 0…1, 0…5 V or 0…10 V depending on the model. The analog output is preset to correspond to the pressure range 600…1100 hPa. Using the proprietary protocol or the MODBUS-RTU protocol it is possible:

• to associate the analog output to a different pressure range, within the full measuring range;
• to add/remove an offset to the output minimum value (e.g., change from 0…10 V to 2…10 V or from 4…20 mA to 0…20 mA);
• to reverse the direction of the output, so that the output decreases as the meas-urement increases.

In the event of a measurement error, the output goes to a value 10% higher than the full scale (e.g., 11 V if the output is 0…10 V or 22 mA if the output is current).

Status of the transmitter:
The transmitter version with LCD option has two front LEDs: the green LED indicates the presence of the external power supply (blinks once per second), the red LED indi-cates the presence of any measurement errors (normally off, it blinks twice per sec-ond if in error).

ASCII PROPRIETARY PROTOCOL

To use the ASCII proprietary protocol, it is necessary to connect the instrument to the PC via a RS485/USB or RS485/RS232 converter and use a standard serial communica-tion program. In the serial communication program, set the COM port number to which the instrument is connected and the communication parameters as follows:

• If the MODBUS-RTU protocol is set as the operating protocol in the instrument (default), set the Baud Rate 57600 and the parameters 8N2 in the serial commu-nication program, then power cycle the instrument and send the command @ within 10 seconds from the instrument power on.
• If the proprietary protocol is already set as the operating protocol in the instru-ment, it is possible to operate with Baud Rate 57600 and parameters 8N2 by sending the command @ within 10 seconds from the instrument power on, or you can let the 10 seconds pass without sending the command @ and operate with the communication parameters set in the instrument (default 19200, 8E1).

To change the instrument configuration, the serial command CAL USER ON must be sent first (the instrument replies with USER CAL MODE ON). The command CAL USER ON is automatically disabled after a few minutes of inactivity. If the settings should be only read, the command CAL USER ON is not required.
Below is the list of the serial commands.

Instrument information:

Protocol:

instrument power on. It must be sent within 10 seconds from instrument power on.
DPn| &|| Sets the operating protocol:

§ Proprietary if n=0

§ MODBUS-RTU if n=1

Default : MODBUS-RTU (n=1)

GP| & n|| Reads the operating protocol set in the instrument.
SM| &|| Activates the MODBUS-RTU protocol immediately.
CMAn| &|| Sets the MODBUS-RTU address (1…247) to n.

Default : 1

RMA| & n|| Reads the MODBUS-RTU address.

Warning : after sending the DP1 command, the instrument remains with the proprietary pro-tocol. Send the command SM to activate the MODBUS-RTU protocol immediately, or power cy-cle the instrument.

communication parameters:

§ 1200 if n=0                      ▪ 19200 if n=4

§ 2400 if n=1                      ▪ 38400 if n=5

§ 4800 if n=2                      ▪ 57600 if n=6

§ 9600 if n=3                      ▪ 115200 if n=7

Default : 19200 (n=4)

RMB| & n|| Reads Baud Rate setting
CMPn| &|| Sets parity and stop bits:

§ 8N1 if n=0 [No parity, 1 stop bit]

§ 8N2 if n=1 [No parity, 2 stop bits]

§ 8E1 if n=2 [Even parity, 1 stop bit]

§ 8E2 if n=3 [Even parity, 2 stop bits]

§ 8O1 if n=4 [Odd parity, 1 stop bit]

§ 8O2 if n=5 [Odd parity, 2 stop bits] The number of data bits is fixed to 8.

Default : 8E1 (n=2)

RMP| & n|| Reads the setting of parity and stop bits.
CMWn| &|| Sets waiting time after transmission with MODBUS-RTU protocol:

§ Immediate reception if n=0 (violates protocol)

§ Waiting 3.5 characters if n=1 (respects protocol)

Default : Immediate reception (n=0)

RMW| & n|| Reads the setting of waiting time after transmission with MODBUS- RTU protocol.

Measurements reading:

the sending interval, use the command MT.
S2| & Measurements| Prints the measurements in the following sequence:

§ Pressure

§ Power supply voltage

§ Internal temperature

§ Measurement error: 0 = no error

1 = pressure error

2 = internal temperature error

3 = pressure and internal temperature error

The measurements are expressed in the set units of measurement.

MTn| &|| Sets the measurement interval to n seconds (1…30 s).

Default : 1

NT| & n|| Reads the measurements sending interval.

Units of measurement:

§ Torr if n=0

§ Pa if n=1

§ hPa if n=2

§ kPa if n=3

§ mbar if n=4

§ psi if n=5

§ kg/cm2 if n=6

§ mmH2O if n=7

§ mmHg if n=8

§ inH2O if n=9

§ inHg if n=10

§ atm if n=11

§ bar if n=12

Default : 2 Þ hPa

RU| & n|| Reads the pressure unit of measurement.
TTn| &|| Sets the temperature unit of measurement of index n:

§ °C if n=0

§ °F if n=1

Default : 0 Þ °C

HT| & n|| Reads the temperature unit of measurement.

Pressure measurement offset:

be entered, see Note 1 below.

The offset must be within the ±10 hPa range or equiva- lent range in the set unit of measurement, if different from hPa.

Default : 0

RO| & n|| Reads the pressure measurement offset (see Note 1

below).

Restoring the factory configuration:

Analog output:

Current output
CAOn| &|| Enable/disable the offset of the current analog output:

§ Offset disabled if n=0 (0…20 mA)

§ Offset enabled if n=1 (4…20 mA)

Default : Offset enabled (n=1)

RAO| & n|| Reads the setting of the offset for the current analog output.
CASOn| &|| Sets the direct or reversed correspondence between cur- rent analog output and pressure:

§ Min. mA Þ Min. press., Max. mA Þ Max. press. if n=0

§ Min. mA Þ Max. press., Max. mA Þ Min. press. if n=1

Default : Direct correspondence (n=0)

RASO| & n|| Reads the type of correspondence (direct or reversed) between current analog output and pressure.
CALn| &|| Sets n as the minimum pressure value for the current analog output.

For the value n to be entered, see Note 1 below.

Default : 60000 (=600.00 hPa)

RAL| & n|| Reads the minimum pressure value for the current analog output (see Note 1 below).
CAHn| &|| Sets n as the maximum pressure value for the current analog output.

For the value n to be entered, see Note 1 below.

Default : 110000 (=1100.00 hPa)

RAH| & n|| Reads the maximum pressure value for the current ana- log output (see Note 1 below).
RAF| & 0

Minimum value Maximum value

| Simultaneously provides the information obtainable with the RAL e RAH commands.
Voltage output
CVOn| &|| Enable/disable the offset of the voltage analog output:

§ Offset disabled if n=0 (0…1/0…5/0…10 V)

§ Offset enabled if n=1 (0,2…1/1…5/2…10 V)

Default : Offset disabled (n=0)

RVO| & n|| Reads the setting of the offset for the voltage analog output.
CVSOn| &|| Sets the direct or reversed correspondence between volt- age analog output and pressure:

§ Min. V Þ Min. press., Max. V Þ Max. press. if n=0

§ Min. V Þ Max. press., Max. V Þ Min. press. if n=1

Default : Direct correspondence (n=0)

RVSO| & n|| Reads the type of correspondence (direct or reversed) between voltage analog output and pressure.
CVLn| &|| Sets n as the minimum pressure value for the voltage analog output.

For the value n to be entered, see Note 1 below.

Default : 60000 (=600.00 hPa)

(see Note 1 below).
CVHn| &|| Sets n as the maximum pressure value for the voltage analog output.

For the value n to be entered, see Note 1 below.

Default : 110000 (=1100.00 hPa)

RVH| & n|| Reads the maximum pressure value for the voltage ana- log output (see Note 1 below).
RVF| & 0

Minimum value Maximum value

| Simultaneously provides the information obtainable with the RVL e RVH commands.

Note 1 : The value is an integer, expressed in the set unit of measurement and must take into account the resolution corresponding to the set unit of measurement (see the column “ASCII proprietary protocol” of the table on page 5). For example, if the set unit of measurement is hPa, the value is in hundredths of hPa (60000 equals 600.00 hPa. The number is automatically converted if the unit of measurement is changed (which must therefore be set first).

MODBUS-RTU PROTOCOL

By default, the instrument has MODBUS address 1 and communication parameters 19200, 8E1. The address and the communication parameters can be changed by using the appropriate serial commands of the proprietary protocol or, alternatively, directly with MODBUS commands by changing the value of the Coils and Holding Registers de-scribed later. The MODBUS-RTU protocol, if set as the operating protocol (default), is active after 10 seconds from the instrument power on. In order to change the instrument configuration using the MODBUS-RTU protocol, the value 1 must be written first in the Coil with address 1. Below is the list of registers.

Input Registers:

0 = no error

1 = pressure error

2 = internal temperature error

3 = pressure and internal temperature error

| 16-bit Integer

Coils:

Bit
1| Enable configuration change:

0=no (default), 1=yes.

The changes to Coils and Holding Registers will be accept- ed only if this register is set to 1.

| Bit
2| Sets waiting time after transmission with MODBUS-RTU pro- tocol:

0=immediate reception (default); 1=waiting 3.5 characters.

| Bit
3| Enable/disable the offset of the current analog output: 0=offset disabled (0…20 mA)

1=offset enabled (default, 4…20 mA)

| Bit
4| Sets the direct or reversed correspondence between current analog output and pressure:

0=direct (default, Min. mA Þ Min. press., Max. mA Þ Max. press.)

1=reversed (Min. mA Þ Max. press., Max. mA Þ Min. press.)

| Bit
Address| Description| Format
---|---|---
6| Enable/disable the offset of the voltage analog output: 0=offset disabled (default, 0…1/0…5/0…10 V) 1=offset enabled (0,2…1/1…5/2…10 V)| Bit
7| Sets the direct or reversed correspondence between voltage analog output and pressure:

0=direct (default, Min. V Þ Min. press., Max. V Þ Max. press.)

1=reversed (Min. V Þ Max. press., Max. V Þ Min. press.)

| Bit

Holding Registers:

1=2400;

2=4800;

3=9600;

4=19200 (default);

5=38400;

6=57600;

7=115200.

| 16-bit Integer
1| RS485 parity and stop bits: 0=8N1;

1=8N2;

2=8E1 (default); 3=8E2;

4=8O1;

5=8O2.

[N=no parity, E=even parity, O=odd parity]| 16-bit Integer
2| Instrument address for the MODBUS-RTU protocol (1…247, default=1).| 16-bit Integer
3| Pressure unit of measurement:

0 Þ Torr, 1 Þ Pa, 2 Þ hPa, 3 Þ kPa, 4 Þ mbar,

5  Þ psi,  6  Þ kg/cm2,  7  Þ mmH2O,  8  Þ mmHg,

9  Þ mmH2O,  10  Þ inHg,  11  Þ atm,  12  Þ bar

Default : 2 Þ hPa

| 16-bit Integer
4| Offset added to the measured pressure value. For the value, see Note 3 below.

The offset must be within the ±10 hPa range or equivalent range in the set unit of measurement, if different from hPa.

Default : 0.

| 16-bit Integer
5| Temperature unit of measurement:

0 Þ °C, 1 Þ °F

Default : 0 Þ °C

| 16-bit Integer
6| Measurement interval in seconds (1…30, default=1).| 16-bit Integer
8| Minimum pressure value for the current analog output. For the value, see Note 3 below.

Default : 60000 (=600.00 hPa)

| 32-bit Integer (2)
Address| Description| Format
---|---|---
10| Maximum pressure value for the current analog output. For the value, see Note 3 below.

Default : 110000 (=1100.00 hPa)

| 32-bit Integer (2)
13| Minimum pressure value for the voltage analog output. For the value, see Note 3 below.

Default : 60000 (=600.00 hPa)

| 32-bit Integer (2)
15| Maximum pressure value for the voltage analog output. For the value, see Note 3 below.

Default : 110000 (=1100.00 hPa)

| 32-bit Integer (2)

Note 2: The value is a 32-bit integer; two consecutive registers starting from the one indicated must be accessed to read it. The register with lower address contains the least significant bits.

Note 3: The value is an integer, expressed in the set unit of measurement and must take into account the resolution corresponding to the set unit of measurement (see the column “Modbus protocol IR 0” of the table on page 5). For example, if the set unit of measurement is hPa, the value indicates hundredths of hPa (60000 equals 600.00 hPa. The number is automatically converted if the unit of measurement is changed (which must therefore be set first).

SAFETY INSTRUCTIONS

General safety instructions
The instrument has been manufactured and tested in accordance with the safety standard EN61010-1:2010 “Safety requirements for electrical equipment for meas-urement, control and laboratory use” and has left the factory in perfect safety tech-nical conditions. The instrument proper operation and operating safety can be ensured only if all standard safety measures as well as the specific measures described in this manual are followed. The instrument proper operation and operating safety can be ensured only in the cli-matic conditions specified in this manual.Do not use the instruments in places where there are:

• Corrosive or flammable gases.
• Direct vibrations or shocks to the instrument.
• High-intensity electromagnetic fields, static electricity.

User obligations
The instrument operator shall follow the directives and regulations below that refer to the treatment of dangerous materials:

• EEC directives on workplace safety.
• National law regulations on workplace safety.
• Accident prevention regulations.

ORDERING CODES

ACCESSORIES

• SWD10F 100…240 Vac / 12 Vdc – 1A power supply. Includes adapter cable with jack connector on the power supply side and free wires on the instrument side.
• HP3517ITC1.2 Temperature and relative humidity combined probe. 4-pole M12 connector. T/RH measuring range: -40…+105 °C / 0…100%. Stem dimensions: Ø14 x 135 mm. Material: PBT. Cable length: 2 m.
• HD9007A-1… 12-ring protection from solar radiations. Supplied with mounting bracket. For the HP3517ITC1… probe.
• HD9007A-2… 16-ring protection from solar radiations. Supplied with mounting bracket. For the HP3517ITC1… probe.
• HD9007T26.2 Fitting for Ø 14 mm probes for the protections from solar radiations HD9007A-1 and HD9007A-2.

EU DECLARATION OF CONFORMITY

WARRANTY

Delta OHM is required to respond to the “factory warranty” only in those cases provided by Legislative Decree 6 September 2005 – n. 206. Each instrument is sold after rigorous inspections; if any manufacturing defect is found, it is necessary to contact the distributor where the instrument was purchased from. During the warranty period (24 months from the date of invoice) any manufacturing defects found will be repaired free of charge. Misuse, wear, neglect, lack or inefficient maintenance as well as theft and damage during transport are excluded. Warranty does not apply if changes, tampering or unauthorized repairs are made on the product. Solutions, probes, electrodes and microphones are not guaranteed as the improper use, even for a few minutes, may cause irreparable damages. Delta OHM repairs the products that show defects of construction in accordance with the terms and conditions of warranty included in the manual of the product. For any dispute, the competent court is the Court of Padua. The Italian law and the “Convention on Contracts for the International Sales of Goods” apply.

TECHNICAL INFORMATION

The quality level of our instruments is the result of the continuous product development. This may lead to differences between the information reported in the manual and the instrument you have purchased. In case of discrepancies and/or inconsistencies, please write to sales@deltaohm.com. Delta OHM reserves the right to change technical specifications and dimensions to fit the product requirements without prior notice.

DISPOSAL INFORMATION

Electrical and electronic equipment marked with specific symbol in compliance with 2012/19/EU Directive must be disposed of separately from household waste. European users can hand them over to the dealer or to the manufacturer when purchasing a new electrical and electronic equipment, or to a WEEE collection point designated by local authorities. Illegal disposal is punished by law. Disposing of electrical and electronic equipment separately from normal waste helps to preserve natural resources and allows materials to be recycled in an environmentally friendly way without risks to human health.

GHM GROUP – Delta OHM
Delta Ohm S.r.l. a socio unico Via Marconi 5 | 35030 Caselle di Selvazzano | Padova | ITALY Phone +39 049 8977150 | Fax +39 049 635596 www.deltaohm.com | sales@deltaohm.com

References

• Senseca - Measuring, monitoring, testing and control instruments

Read User Manual Online (PDF format)

Download This Manual (PDF format)

Download this manual  >>