COMET SYSTEM T2314 Atmospheric Pressure Transmitter Instruction Manual

COMET SYSTEM T2314 Atmospheric Pressure Transmitter

With RS232/RS485 Serial Output

The Atmospheric Pressure Transmitter is a device that measures atmospheric pressure for various applications. The device comes in two versions: T2314 and T2414 and has two output options: RS232 and RS485. The output is galvanically isolated, which helps to prevent electrical interference. The transmitter version TxxxxL comes with a watertight male connector instead of a cable gland for easy connection/disconnection of the communication cable. The male Lumberg connector RSFM4 has protection IP67. Models marked TxxxxZ are non-standard versions of the transmitters, and their description is not included in this manual. The device is set by the manufacturer to the following parameters: communication protocol: Modbus RTU, device address: 01H, communication speed: 9600Bd, without parity, 2 stop bits switched ON; display: hPa; pressure unit: 0 hPa (absolute pressure).

Device Installation

The cable should be led in one line, i.e. NOT to “tree” or “star”. The termination resistor should be located at the end. For a short distance, other topology is allowed. Terminate the network by a termination resistor. The value of the resistor is recommended to be about 120 Ω. For short distances, the termination resistor can be left out. The cable should not be led in parallel along the power cabling. Safety distance is up to 0.5 m, otherwise, undesirable induction of interference signals can appear.

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

Info Mode

If in doubt of the setting of the installed device, verification of its address is enabled even without using a computer. Power should be connected. Devices with RS232 interface have addresses always set to one. Unscrew the device cover and shortly press the button next to the connection terminals (the jumper should be opened). The actual adjusted address of the device is displayed on the LCD display at the decimal base, for HWg-Poseidon’s communication protocol there is shown a number corresponding with the ASCII address code. Next press of the button exits info mode and actual measured values are displayed.

Note: No measurement and communication are possible during info mode. If the device stays in info mode for longer than 15 s, the device automatically returns to the measuring cycle.

The setting of Pressure Correction for Altitude

If there is a necessary need to read the value of atmospheric pressure corrected with respect to altitude, it is possible to set a corresponding pressure offset for this altitude. It is possible to do it with Users’ software. This value is then automatically added to the measured pressure value. The resultant value of pressure with added correction for altitude must be between 300 hPa and 1350 hPa (from 4.351 PSI to 19.580 PSI). Outside this range, the device sends a value of Error 2!

Transmitter with RS232

Connection: see Appendix B.

Transmitter with RS485

Connection: see Appendix B.

Description of Communication Protocols

© Copyright: COMET SYSTEM, Ltd. It is prohibited to copy and make any changes in this manual, without explicit agreement of the company COMET SYSTEM, Ltd. All rights reserved. COMET SYSTEM, Ltd. makes constant development and improvement of their products. The manufacturer reserves the right to make technical changes to the device without previous notice. Misprints reserved. The manufacturer is not responsible for damages caused by using the device in conflict with this manual. To damages caused by using the device in conflict with this manual cannot be provided free repairs during the warranty period. Carefully read the instruction manual before the first device connection. Contact address of this device’s producer:

• COMET SYSTEM, s.r.o.
• Bezrucova 2901
• 756 61 Roznov pod Radhostem
• Czech Republic  www.cometsystem.com

Instruction Manual

The device is designed for the measurement of atmospheric pressure at hPa, PSI, inHg, mBar, oz/in2, mmHg, inH2O and kPa. It is possible to set pressure correction for altitude (offset). The device setting is provided by user’s software, see later. Device T2314 communicates via link RS232, and device T2414 via 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 the manufacturer to Modbus RTU communication protocol. If you would like to use a different communication protocol then Modbus RTU, it is necessary to preset them through the user’s software – see latter. The pressure sensor is placed inside the electronic case. The measured value is optionally shown on LCD display. The display can be switched OFF too. Use the user’s software TSensor for setting of all device parameters (recommended). It is free to download at www.cometsystem.com. It supports making 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 the 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 a 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. Models marked TxxxxZ are non-standard versions of the transmitters. The description is not included in this manual.
Please read the instruction manual before the first device connection.

Device setting from the manufacturer

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

• communication protocol: Modbus RTU
• device address: 01H
• communication speed: 9600Bd, without parity, 2 stop bits
• display: switched ON
• pressure unit: hPa
• correction for altitude: 0 hPa (absolute pressure)

Device installation

The device is designed for wall mounting. There are two mounting holes at the sides of the case. Don’t connect the device while the power supply voltage is on. Interconnection terminals for T2314 and T2414 devices are accessible after unscrewing four screws and removing the lid. 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 the smaller terminal hole and lever by him. Do not forget to tighten the glands and case lid with inserted packing after the cables connect. It is necessary for warranting of protection IP54. Connect complementary female connectors for T2314L and T2414L transmitters in accordance with the table in Appendix B of this manual. The working position is with a communication cable entering from the top side. Devices T2314 are supplied with a connection cable equipped with a connector for connection to the RS232 interface. For devices with RS485 output, there is recommended to use shielded twisted copper cable, with a maximal length of 1200m. The cable must be located at indoor rooms. The nominal cable impedance should be 100 Ω, loop resistance max. 240 Ω, cable capacity max. 65 pF/m. The outside diameter of the cable for the T2414 connection must be from 3 to 6.5 mm. A suitable cable is e.g. SYKFY 2x2x0.5 mm2, where one wire pair serves for device powering and the other pair for the communication link. For devices T2314L and T2414L use cable with respect to female connector parameters. Do NOT connect shielding at the connector side. The cable should be led in one line, i.e. NOT to „tree“ or „star“. The termination resistor should be located at the end. For short distances, another topology is allowed. Terminate the network by a termination resistor. The value of the resistor is recommended about 120. For short-distance termination, the resistor can be left out. The cable should not be led in parallel along the power cabling. Safety distance is up to 0.5 m, otherwise, undesirable induction of interference signals can appear. The electrical system (wiring) may do only workers with the required qualification by rules in operation.

Info mode

If in doubt of the setting of the installed device, verification of its address is enabled even without using the computer. Power should be connected. Devices with RS232 interface have addresses always set to one. Unscrew the device cover and shortly press the button next to the connection terminals (the jumper should be opened). The actual adjusted address of the device is displayed on LCD display at the decimal base, for HWg-Poseidon’s communication protocol there is shown a number corresponding with the ASCII address code. Next press of the button exits info mode and actual measured values are displayed.
Note: No measurement and communication is possible during info mode. If the device stays in info mode for longer than 15 s, the device automatically returns to the measuring cycle.

Setting of pressure correction for altitude
If there is necessary to read the value of atmospheric pressure corrected with respect to altitude, it is possible to set the corresponding pressure offset for this altitude. It is possible to do it with Users’ software. This value is then automatically added to the measured pressure value. The resultant value of pressure with added correction for altitude must be between 300 hPa and 1350 hPa (from 4.351 PSI to 19.580 PSI). Outside this range device sends value of Error 2!

Dimensions

T2314

• Transmitter with RS232

T2414

• Transmitter with RS485

T2314L, T2414L

• Connection: see Appendix B

Typical application wiring, the connection of terminals

T2314 – power from communication port T2314 – power from external voltage source

T2414 – RS485

Description of communication protocols

A detailed description of each communication protocol including examples of communication is available in the individual document “Description of communication protocols of Txxxx series” which is free to download at www.cometsystem.com.
Note: After switching ON the power of the device it can last up to 2 s before the device starts to communicate and measure!

Modbus RTU
Control units communicate on the master-slave principle in half-duplex operation. Only the master can send a request and only the addressed device responds. During sending of request no other slave station should respond. During communication, data transfer proceeds in binary format. Each Byte is sent as an eight-bit data word in the format: 1 start bit, data word 8 bit (LSB first), 2 stop bits1, without parity. The device supports communication speed from 110Bd to 115200Bd. Sent request and response have the syntax: ADDRESS OF DEVICE – FUNCTION – Modbus CRC

Supported functions

• 03 (0x03): Reading of 16-bit registers (Read Holding Registers)
• 04 (0x04): Reading of 16-bit input gates (Read Input Registers)
• 16 (0x10): Setting of more 16-bit registers (Write Multiple Registers)

Jumper and button
The jumper and button are located next to the connection terminals. If the communication protocol Modbus is selected the function of the jumper and button is as follows:

• Jumper opened – device memory is protected from writing, from device side it is only enabled to read measured value, writing to memory is disabled (no change of device address, communication speed and LCD setting is enabled).
• Jumper closed – writing to device memory is enabled by means of User’s software.
• Jumper opened and button shortly pressed – device goes to Info mode, see chapter „Info mode“.
• Jumper closed and button pressed for longer than six seconds – causes restoring of manufacturer setting of communication protocol, i.e. sets Modbus RTU communication protocol, device address sets to 01h and communication speed to 9600Bd – after button press there is “dEF” message blinking at LCD display. Six seconds later message “dEF” stays shown, it means the manufacturer setting of the communication protocol is done.

Modbus registers of the device

Explanation

• • depends on device setting (by User’s software)
• Int10 register is in format integer10
• R register is designed only for reading
• W* register is designed for writing, for details see file “Description of communication protocols of Txxxx series”
• X register addresses are indexed from zero – register 0x31 is physically sent as value 0x30, 0x32 as 0x31 (zero-based addressing).

Note: In case there is a need for reading of measured values from the device with higher resolution than one decimal, measured values in the device are stored also in „Float“ format, which is not directly compatible with IEEE754.

Protocol compatible with Advantech ADAM standard
Control units communicate on the master-slave principle in half-duplex operation. Only master can send requests and only the addressed device responds. During sending request any of slave devices should respond. During communication data is transferred in ASCII format (in characters). Each Byte is sent as two ASCII characters. Device supports communication speed from 1200Bd to 115200Bd, parameters of the communication link are 1 start bit + eight-bit data word (LSB first) + 1 stop bit, without parity.

Jumper

Jumper is located next to the connection terminals. If a communication protocol compatible with standard Advantech-ADAM is selected, its function is the following:

• If the jumper during switching ON the power is closed, the device always communicates with the following parameters regardless stored setting in the device: communication speed 9600 Bd, without checksum, device address 00h
• If the jumper during switching ON the power is not closed, the device communicates in accordance with the stored setting.
• If the jumper is closed during device operation, the device temporarily changes its address to 00h, it will communicate in the same communication speed as before closing the jumper and will communicate without checksum. After the jumper is opened setting of the address and checksum is reset in accordance with values stored in the device.
• Communication speed and checksum are possible to change only if the jumper is closed.
• Jumper closed and button pressed for longer than six seconds – causes restoring of manufacturer setting of communication protocol, i.e. sets Modbus RTU communication protocol, device address sets to 01h and communication speed to 9600Bd – after button press there is “dEF” message blinking at LCD display. Six seconds later message “dEF” stays shown, it means the manufacturer setting of the communication protocol is done.

ARION communication protocol AMiT company
The device supports communication protocol ARiON version 1.00. For more details see file “Description of communication protocols of Txxxx series” or www.amit.cz.

Communication with HWg Poseidon units
The device supports communication with HWg-Poseidon units. For communication with this unit set the device with setup software TSensor to communication protocol HWg–Poseidon and set the correct device address. This communication protocol supports read temperature at °C, relative humidity, one of computed value (dew point temperature or absolute humidity) and barometric pressure at kPa (depending by device type). For atmospheric pressure correction to altitude setting there is Users software TSensor.

Jumper and button
If communication with HWg Poseidon unit is selected, the function of the jumper and button is as follows:

• Jumper opened and the button was shortly pressed – the device goes to Info mode, see chapter „Info mode“.
• Jumper closed and button pressed for longer than six seconds – causes restoring of manufacturer setting of communication protocol, i.e. sets Modbus RTU communication protocol, device address sets to 01h and communication speed to 9600Bd – after button press there is “dEF” message blinking at LCD display. Six seconds later message “dEF” stays shown, it means the manufacturer setting of the communication protocol is done.

Error States of the device
The device continuously checks its state during operation. In case the error is found LCD displays the corresponding error code:

Error 0
The first line displays „Err0“.
Check sum error of the stored setting inside the device’s memory. This error appears if an incorrect writing procedure to the device’s memory occurred or if damage of calibration data appeared. At this state device does not measure and calculate values. It is a serious error, contact the distributor of the device to fix.

Error 2
There is a reading „Err2“ on the LCD display. A pressure measurement error occurred. The value read from the device is -999.9.

• This state occurs if the measured pressure value with added correction for altitude is outside of the range from 300 hPa to 1350 hPa (from 4.351 PSI to 19.580 PSI) or the pressure sensor is damaged. Please check the setting of pressure correction for altitude with the User’s software.

Error 4
There is a reading „Err4“ on the LCD display. It is an internal device error during pressure sensor initialization. Under this condition, the device does NOT measure atmospheric pressure. The value read from the device is -999.9. A pressure sensor is probably damaged. It is a serious error, contact the distributor of the device.

Readings on LCD display
hPa, PSI, inHg, Reading next to this symbol is measured pressure or error state of value. If the selected pressure unit is mBar or oz/in2 or mmHg or inH2O or kPa, there is shown only value (number) without the corresponding pressure unit! symbol 3 nearby left display margin Is on if the jumper is closed.

Technical parameters of the device

RS 485 Interface:

• Receiver-Input Resistance: 96 kΩ
• Devices on bus: max. 256 (1/8 Unit Receiver Load)

Measuring parameters:

Atmospheric pressure (T5410 only)

• Response time atmospheric pressure2: t90 <44s
• Recommended calibration interval: 1 year
• Measuring interval and LCD display refresh: 2 s
• Power: 9 to 30 V dc

2 There is possible to change the response time. For more details see file “Description of calibration and adjustment procedure.pdf”, which is installed together with Users software.

• Consumption: T2314 (RS232) 6 mA T2414 (RS485) max. 0.5 W
• Protection: IP54

Operating conditions

• Operating temperature range: -30 to +80 °C, over +70°C switch LCD display off
• Operating relative humidity range: 0 to 100 %RH
• Outer influence in accordance with Czech National Standard 33-2000-3: normal environment with those specifications: AE1, AN1, AR1, BE1
• Working position: communication cable is entering from the top side
• Electromagnetic compatibility: complies EN 61326-1

Not allowed manipulation
It is not allowed to operate the device under conditions other than those specified in technical parameters. Devices are not designed for locations with chemically aggressive environments.

Do not use the device in an explosive environment

• Storing conditions: temperature -30 to +80 °C, humidity 0 to 100 %RH without condensation
• Dimensions: see dimensional drawings
• Weight: approximately T2314 cca 215 g, T2314L cca 135 g, T2414(L) cca 135 g
• Material of the case: ASA

End of operation
The device itself (after its life) is necessary to liquidate ecologically!

Technical support and service
Technical support and service is provided by the distributor. For contact see the warranty certificate.

Appendix A

Connection of ELO E06D (RS232/RS485) and ELO 214 (USB/RS485) converters

The ELO E06D converter is an optional accessory for the connection of the transmitter with RS485 interface to the PC via serial port RS232. Connect the connector marked RS232 directly to the PC, and connect the power to the connector marked RS485. Power voltage +6V DC from an external acdc adapter connects to pin 9, 0V connects to pin 5. Also mutually connect pin 2 and pin 7. Link RS485 is connected across pin 3 (A+) and pin 4 (B-). The ELO 214 converter is an optional accessory for the connection of the transmitter with RS485 interface to the PC via USB port. Link RS485 is connected across pin 9 (A+) and pin 8 (B-).

Appendix B

Documents / Resources

| COMET SYSTEM T2314 Atmospheric Pressure Transmitter [pdf] Instruction Manual
T2314 Atmospheric Pressure Transmitter, T2314, Atmospheric Pressure Transmitter, Pressure Transmitter, Transmitter
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References

• AMiT redirecting
• AMiT redirecting
• Manufacturer of Dataloggers, Thermometers, Hygrometers,CO2 meters

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