GHM DeltaOHM BAROsense User manual

Operating manual
Barometric transmitter
BAROsense
www.deltaohm.com
English
Ke
ep for future referen
ce.

BAROsense - 2 - V1.2
TABLE OF CONTENTS
1 INTRODUCTION ........................................................................................ 3
2 TECHNICAL SPECIFICATIONS ...................................................................
3 INSTALLATION ......................................................................................... 6
3.1 ELECTRICAL CONNECTIONS ........................................................................ 7
CONFIGURATION AND MEASUREMENT ..................................................... 9
5 ASCII PROPRIETARY PROTOCOL ............................................................ 10
6 MODBUS-RTU PROTOCOL ........................................................................ 15
7 SAFETY INSTRUCTIONS .......................................................................... 18
8 ORDERING CODES .................................................................................. 19

BAROsense - 3 - V1.2
1 INTRODUCTION
BAROsense is a barometric transmitter eq ipped with a precision piezo-resistive
press re sensor with integrated temperat re sensor. The press re and temperat re
meas rements are digitally processed to obtain a press re o tp t val e compensated
over the whole transmitter temperat re operating range.
The sensor is factory calibrated in m ltiple points and has excellent time stability and re-
peatability.
The instr ment has a digital RS 85 o tp t with MODBUS-RTU or proprietary proto-
col. As option, it can be s pplied with an additional analog output, which can be
selected by the user in current or voltage via an internal j mper. The c rrent
o tp t is ser config rable 0...20 mA or 4...20 mA (defa lt), while the voltage o tp t
m st be defined when ordering (0...1 V, 0...5 V or 0...10 V).
The transmitter digital o tp t enables the transmission of the meas rements over
long distances and connects the transmitter to sensors networks.
The press re can be expressed in different ser-selectable nits of meas rement.
Optional LCD display.
Optional inp t for combined temperat re and relative h midity probe.
Also available with optional static port and s pport bracket to minimize the effect of
dynamic press re d e to the wind in open field meas rements.

BAROsense - 4 - V1.2
2TECHNICAL SPECIFICATIONS
Barometric pressure
Sensor Piezoresistive
Meas ring range 300…1100 hPa
Config rable for the analog o tp t: defa lt 600…1100 hPa
Resol tion See table below
Acc racy ± 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
Meas ring range 0…100%
Resol tion 0.1%
Acc racy ± 2.5% (0..85%) / ± 3.5% (85…100%) @ T=23 °C
Temperat re 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, witho t filter)
Long-term stability < 1%/year (@ 23 °C and 30…70%)
Temperature (with optional external T/RH probe)
Sensor PTAT integrated in h midity mod le
Meas ring range -40…+105 °C
Resol tion 0.1 °C
Acc racy ± 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
O tp t RS485 with Modb s-RTU or ASCII proprietary protocol
Optional analog o tp t, selectable in c rrent (0/4…20 mA) or volt-
age (0…1 V, 0…5 V or 0…10 V, depending on the model)
C rrent o tp t load resistance: RL < (Vdc-7)/0,022)
Voltage o tp t load resistance: RL > 10 kΩ
Power s pply BAROsense-M: 7…30 Vdc
BAROsense-1 and BAROsense-5: 8…30 Vdc
BAROsense-10: 15…30 Vdc
Cons mption 4 mA @ 24 Vdc (+ o tp t c rrent if c rrent o tp t is sed)
Connection
Internal screw terminal header / PG7 cable gland for power s pply
and o tp t. 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

BAROsense - 5 - V1.2
Materials Transmitter: Polycarbonate, press re inp t in nickel-plated brass
Static port (optional): ASA
S pport bracket: Al mini m alloy
Ho sing dimensions 120 x 80 x 55
Weight 250 g approx.
570 g approx. the static port with s pport bracket
Protection degree IP65
Units of measurement available and corresponding resolution
With the MODBUS-RTU protocol, two different inp t registers are available for the
press re meas rement, with different resol tion: IR 0 (32-bit) and IR 2 (16-bit).
With the ASCII proprietary protocol, the resol tion is niq e.
Resolution
Unit of
measurement
ASCII proprietary protocol
Modbus protocol IR 0 (32-bit)
Display
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

BAROsense - 6 - V1.2
3INSTALLATION
The transmitter is wall mo nted sing the two holes on the back (open the cover to
access the holes and the terminal header for electrical connections).
109
50
Ø4.4
(2x)
Fig. 3.1: fixing holes
It is advisable to mo nt the transmitter so that the press re inp t is facing down-
wards, in order to red ce the acc m lation of d st and dirt on the inp t.
For o tdoor installation, the se of the transmitter version with static press re port
(BAROsense…K) is recommended, in order to minimize the meas rement error
ca sed by the wind flow on the press re inp t (the meas rement deviation d e to
wind is less than 0.3 hPa @ 20 m/s if the static port is sed). The transmitter version
with static port incl des a s pport bracket s itable for fixing to a Ø30…50 mm mast.
5650
194.5
140
157
Fig. 3.2: transmitter with static pressure port
Static port
S pport bracket
S
ilicone
t be
Transmitter
Mast

BAROsense - 7 - V1.2
3.1 ELECTRICAL CONNECTIONS
The transmitter has an internal screw terminal header.
Fig. 3.3: internal terminal header and selection jumpers
Terminal N° Function
1 RS485 D-
2 GND
3 RS485 D+
4 Power s pply positive (+Vdc)
5 GND
6 GND
7 Analog o tp t (OUT)
The analog o tp t, if present, can be in c rrent or voltage, config rable via the j mp-
er to the right of the terminal header.
Fig. 3. : analog output connection
To the left of the terminal header there is a b ilt-in line termination that can be con-
nected or removed thro gh a short j mper. To connect the termination, place the
short j mper between the “RT” and “CLOSE” indications. To remove the termination,
place the short j mper between the “RT” and “OPEN” indications.
Cable gland Press re inp t
Select IOUT
for c rrent o tp t
RL < (Vdc-7)/0,022
Select VOUT
for voltage o tp t
RL > 10 kΩ

BAROsense - 8 - V1.2
D+
D-
GND
220Ω
220Ω ShieldShield Lmax = 1200m
D+
D-
+
D-
1
2
3
4
GND
D+
+VDC
5GND
D+
D-
Fig. 3.5: RS 85 connection
Other sensors with
RS485 o tp t
Termina
t
ion
Termina
t
ion
PLC, data logger or
RS485/USB or RS485/RS232
converter for PC

BAROsense - 9 - V1.2
CONFIGURATION AND MEASUREMENT
The config ration of the instr ment and the reading of the meas rements can be done
via the RS485 serial o tp t, both with the proprietary protocol and with the MODBUS-
RTU protocol.
In the first 10 seconds after the instr ment power on, it is always active the proprie-
tary protocol. After 10 seconds from power on, the operating protocol is activated,
which by defa lt is the MODBUS-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 defa lt, the instr ment has MODBUS address 1 and comm nication parameters
19200, 8E1. Different parameters can be set sing 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 o tp t is c rrent or voltage depending on the config ration of the IOUT / VOUT
j mper on the board. By defa lt, the c rrent o tp t is 4...20 mA and the voltage o t-
p t is 0...1, 0...5 V or 0...10 V depending on the model.
The analog o tp t is preset to correspond to the press re range 600…1100 hPa.
Using the proprietary protocol or the MODBUS-RTU protocol it is possible:
•to associate the analog o tp t to a different press re range, within the f ll
meas ring range;
•to add/remove an offset to the o tp t minim m val e (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 o tp t, so that the o tp t decreases as the meas-
rement increases.
In the event of a meas rement error, the o tp t goes to a val e 10% higher than the
f ll scale (e.g., 11 V if the o tp t is 0...10 V or 22 mA if the o tp t is c rrent).
Status of the transmitter:
The transmitter version with LCD option has two front LEDs: the green LED indicates
the presence of the external power s pply (blinks once per second), the red LED indi-
cates the presence of any meas rement errors (normally off, it blinks twice per sec-
ond if in error).

BAROsense - 10 - V1.2
5ASCII PROPRIETARY PROTOCOL
To se the ASCII proprietary protocol, it is necessary to connect the instr ment to the
PC via a RS485/USB or RS485/RS232 converter and se a standard serial comm nica-
tion program. In the serial comm nication program, set the COM port n mber to
which the instr ment is connected and the comm nication parameters as follows:
•If the MODBUS-RTU protocol is set as the operating protocol in the instr ment
(defa lt), set the Ba d Rate 57600 and the parameters 8N2 in the serial comm -
nication program, then power cycle the instr ment and send the command @
within 10 seconds from the instr ment power on.
•If the proprietary protocol is already set as the operating protocol in the instr -
ment, it is possible to operate with Ba d Rate 57600 and parameters 8N2 by
sending the command @ within 10 seconds from the instr ment power on, or
yo can let the 10 seconds pass witho t sending the command @ and operate
with the comm nication parameters set in the instr ment (defa lt 19200, 8E1).
To change the instr ment config ration, the serial command CAL USER ON m st be
sent first (the instr ment replies with USER CAL MODE ON). The command CAL USER ON
is a tomatically disabled after a few min tes of inactivity. If the settings sho ld be only
read, the command CAL USER ON is not req ired.
Below is the list of the serial commands.
Instrument information:
Command Reply Description
G0 Model Instr ment model
G1 &Revision| Instr ment hardware revision
G2 SN=nnnnnnnn Instr ment serial n mber
G3 Firm.Ver.=x.y Instr ment firmware revision
G4 Firm.Date=yyyy/mm/dd Date of firmware revision
GC Fact.Calib.Date= yyyy/mm/dd Date of factory calibration
Protocol:
Command Reply Description
@ &| Keeps the proprietary protocol operational even after 10
seconds from instr ment power on. It m st be sent within
10 seconds from instr ment 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 instr ment.
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 instr ment remains with the proprietary pro-
tocol. Send the command SM to activate the MODBUS-RTU protocol immediately, or power cy-
cle the instr ment.