Comet T3319, T3419, T3419P, T7311, T3319P Instruction Manual

Programmable transmitter of temperature, relative

humidity and other derived humidity values

T3319, T3319P, T3419, T3419P

Programmable transmitter of atmospheric pressure,

temperature, relative humidity and other derived

humidity values

T7311, T7411

with RS232 / RS485 serial output

and external probe

Instruction Manual

IE-SNC-T33(4)19+T73(4)11-09 2

Instruction Manual

Device

type

Temperature

Humidity

Pressure

Computed

values

Output

Version

T3319

✓

✓ - ✓

RS232

probe with cable

T3319P

✓

✓ - ✓

RS232

probe for compressed air *)

T3419

✓

✓ - ✓

RS485

probe with cable

T3419P

✓

✓ - ✓

RS485

probe for compressed air *)

T7311

✓

✓ ✓ ✓

RS232

probe with cable

T7411

✓

✓ ✓ ✓

RS485

probe with cable

*) The removable probe for compressed air measurement is noninterchangeable part of the device.
The protection of connector is IP67

Device is designed for measurement of ambient temperature at °C or °F, relative humidity of

air without aggressive ingredients. Measured temperature and relative humidity are recomputed to
humidity expression: dew point temperature, absolute humidity, specific humidity, mixing ratio and
specific enthalpy. Devices T7311 and T7411 support atmospheric pressure measurement at hPa,
PSI, inHg, mBar, oz/in2, mmHg, inH2O and kPa too. It is possible to set pressure correction for
altitude (offset). Device setting is provided by user’s software, see latter. Devices T3319(P) and
T7311 communicates via link RS232 without galvanic isolation, devices T3419(P) and T7411 via
galvanic isolated link RS485. Supported communication protocols are Modbus RTU, protocol
compatible with standard Advantech-ADAM, ARION and communication with HWg–Poseidon
devices. Devices are preset from manufacturer to Modbus RTU communication protocol. If you
would like to use different communication protocol then Modbus RTU, it is necessary preset them
through user’s software – see latter. Temperature, relative humidity eventually pressure sensors are
non-removable device parts (excepting T3319P and T3419P transmitters), pressure sensor is placed
inside the electronic case. Measured and computed values are optionally shown on dual line LCD
display. If there are two values displayed at one LCD line, they are periodically switched between
both readings with period of 4 seconds. Display can be switched OFF totally too.

Use user’s software Tsensor for setting of all device parameters (recommended). It is

free to download at http://www.cometsystem.cz/english/download-transmitters.htm . It supports

make the adjustment of the device too. This procedure is described at file „Calibration manual.pdf“

which is installed commonly with the software. Change of some parameters is possible to do

without user’s software with Windows hyperterminal (change of communication protocol, its
parameters, LCD display setting). It is described in file “Description of communication protocols of
Txxxx series” which is free to download at the same address.

Transmitter version TxxxxL with watertight male connector instead of a cable gland
(RS232) or glands (RS485) is designed for easy connection/disconnection of communication cable.
Male Lumberg connector RSFM4 has protection IP67.
Transmitter version TxxxxP is designed for compressed air measurement up to 25 bars
Models marked TxxxxZ are non-standard versions of the transmitters. Description is not
included in this manual.
Please read instruction manual before the first device connection.

Device setting from the manufacturer

If special setting was not required in the order the device is set from the manufacturer to the
following parameters:

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communication protocol: Modbus RTU
device address: 01
communication speed: 9600Bd, without parity, 2 stop bits
display: switched ON
value displayed at higher line: temperature (temperature / pressure) – by device type
value displayed at lower line: relative humidity only
temperature unit: °C
pressure unit: hPa
preset computed value: dew point temperature
correction for altitude: 0 hPa (absolute pressure)

Device installation

Device is designed for wall mounting. There are two mounting holes at the sides of the case. It
is NOT recommended to use the device for long time under condensation conditions. It could be the
cause of water steam condensation inside the sensor’s cover into water phase. This liquid phase

stays inside sensor’s cover and can’t escape from the cover easily. It can dramatically increase

response time to relative humidity change. If water condensation occurs for longer time it can cause
sensor damage. Similar effect can occur under water aerosol conditions. Don’t connect device while
power supply voltage is on. Interconnection terminals for T3319(P), T3419(P), T7311 and T7411
devices are accessible after unscrewing four screws and removing the lid. Measuring temperature,
relative humidity and eventually pressure sensors are non-removable device parts. Lace the cable
through a gland at the case wall. Connect the cable to terminals with respecting the signal polarity
(see figure). Terminals are self-clamping and can be opened by a suitable screwdriver. For the
opening, insert the screwdriver to smaller terminal hole and lever by him. Do not forget to tighten
glands and case lid with inserted packing after cables connecting. It is necessary for warranting of
protection IP65. Connect complementary female connector for T3319L, T3419L, T7311L and
T7411L transmitters in accordance with the table in Appendix B of this manual.

Devices T3319(P) and T7311 are supplied with connection cable equipped with connector
for connection to RS232 interface. For devices with RS485 output there is recommended to use
shielded twisted copper cable, maximal length 1200m. The cable must be located at indoor rooms.
Nominal cable impedance should be 100 Ω, loop resistance max. 240 Ω, cable capacity max.
65 pF/m. Outside diameter of the cable for T3419(P) and T7411 connection must be from 3 to 6.5
mm. Suitable cable is e.g. SYKFY 2x2x0.5 mm2, where one wire pair serves for device powering
and the other pair for communication link. For devices T3319L, T3419L, T7311L and T7411L use
cable with respect to female connector parameters. Do NOT connect shielding at connector side.

The cable should be led in one line, i.e. NOT to „tree“ or „star“. Termination resistor should

be located at the end. For short distance other topology is allowed. Terminate the network by a
termination resistor. The value of the resistor is recommended about 120 . For short distance
termination resistor can be left out.

The cable should not be led in parallel along power cabling. Safety distance is up to 0.5 m,
otherwise undesirable induction of interference signals can appear.

Electrical system (wiring) may do only worker with required qualification by rules in
operation.

The devices T3319P and T3419P are designed to measure pressured air. It is good to mount
probe directly into high pressure area (i.e. air pressured pipe) if it is possible. There is other
possibility to use flow chamber SH-PP, see Appendix C.

Before you remove probe of the transmitter TxxxxP, make sure that the pressure in a
pressure chamber (duct, pipe …) and the ambient pressure are in equilibrium

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Dimensions – T3319(P), T7311

transmitter with RS232
serial output

probe for compressed
air measurement

Typical application wiring of T3319(P) and T7311

power from communication port power from external voltage source

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Dimensions – T3419(P), T7411

transmitter with RS485
serial output

probe for compressed
air measurement

Typical application wiring of T3419(P), T7411,
connection of terminals