FAQs

Check RS485 wiring, address, baud rate, parity, stop bits, endianness, and byte swap settings. SENTRO X uses MODBUS RTU over 2-wire half duplex RS485.

The default address is 1, default parity is Even, default stop bits are 1, and default baud rate is 115200.

Check the Controller to Remote Sensor wiring, including +V, 0 V, B and A connections, cable length, and the rBloc/Remote Sensor terminals.

Also confirm the gBloc is correctly installed and that the approved cable or conduit arrangement meets the certification requirements.

Check the Gas Inlet Port and perform Zero and Span response checks. The manual states that IP65 does not imply that the equipment will detect gas during and after exposure to those conditions.

If response is still not as required, replace the Gas Inlet Cover and follow calibration or service guidance.

No. To maintain explosion protection, SENTRO X must only be serviced and repaired by Trolex Ltd or a local Trolex service agent approved by Trolex Ltd.

The manual references IEC/EN 60079-19 for repair guidance.

SENTRO X is configured to always de-energise relay coils when power is absent as a fail-safe condition.

Relay behaviour should be considered when designing external intrinsically safe alarm or control circuits.

If the Gas Inlet Port is compromised and SENTRO X does not respond to gas as required, fit a replacement Gas Inlet Cover to uphold the IP rating.

The manual lists Replacement Gas Inlet Cover part number P5600.130.SP.

Ensure the gas concentration has receded, then reset the pellistor using the on-screen prompt.

The manual warns that resetting while gas is present may cause cell damage and the gBloc should be replaced. Calibration is recommended after exposure to excessive gas concentrations.

Above full scale, SENTRO X shows over-range behaviour and the analogue output follows the over-range characteristics. At 105% of full scale the analogue output is listed as 20.8 mA or 2.08 V, with fault output values available at 22 mA or 2.2 V.

For pellistor sensors above 100% full scale, SENTRO X enters Pellistor Protect.

Under-range means the gas concentration is below -10% of full scale.

Drift mute does not affect under-range alarms or faults, so the condition should be investigated rather than hidden by Drift mute.

Configuration timeout means there has been a three-minute timeout on user activity during configuration.

SENTRO X automatically returns to the main gas sensing screen after inactivity. During maintenance routines, the timeout is extended to ten minutes and the maintenance test is cancelled if it times out.

No Bloc timeout means the Insert Bloc screen has timed out. The manual describes a timeout fault if no sensing Bloc is inserted within five minutes of operation.

Insert the correct gBloc and follow on-screen prompts.

Cell Bloc error means the gBloc has reported a problem.

Check the installed gBloc and follow maintenance or replacement procedures. If the condition remains, contact Trolex.

No Bloc signal means no signal has been received from the gBloc.

Check that the gBloc is correctly inserted and that the correct Remove Bloc procedure is used before removal or replacement.

Low supply voltage means the supply voltage is below the specified limit.

Check that the approved intrinsically safe supply and cable resistance are capable of maintaining the required minimum operating voltage at the sensor.

Watchdog test fail means the watchdog test was under-performed or failed.

The watchdog test function gives instructions on device and the device reboots as part of the test.

RAM health critical indicates an uncorrectable RAM error.

This is a high-priority diagnostic fault and should be escalated through Trolex support if it remains.

System program corrupt indicates a program or flash error.

This is a fault condition. If it remains after the appropriate clear or recovery steps, contact Trolex for support.

Ethernet card MAC means no MAC address was found for the Ethernet Card.

Check the Ethernet Card installation and configuration. If the fault remains, follow the Trolex support route.

Card configuration means the I/O cards are in an incorrect slot.

Check that extension cards are installed according to the manual: the Ethernet Card occupies Slot B only, and relay card arrangements must match the permitted configuration.

Info checksum indicates an error in the boot sequence and is listed as priority 2 in the diagnostic table.

If the condition cannot be cleared after resolution, contact Trolex for further information.

Settings checksum indicates an error in the boot sequence and is listed as the highest-priority diagnostic message.

Resolve the underlying condition and use the Clear prompt if available. If the fault remains, contact Trolex.

Diagnostic messages can be cleared using the Clear prompt after the fault condition has been resolved.

If the fault condition remains after clearing is attempted, contact Trolex for further information.

SENTRO X provides on-device diagnostic messages when a Fault is activated. If multiple events occur, diagnostic or fault messages take priority based on severity order.

The manual lists diagnostic priorities from Settings checksum through Under-range.

SENTRO X prioritises Fault states over Gas Sensing, Maintenance, Warning, Alarm, Pellistor Lockout, and Over-range states.

If a previous state was latched before the fault occurred, clearing the fault returns the device to that previously latched state. Clearing a fault clears all faults that may have occurred previously.

If a dangerous level of gas concentration is detected by the instrument, leave the area immediately.

Follow site emergency procedures and local safety rules.

Calibration must be carried out by competent personnel with appropriate accreditation.

The manual also states that maintenance must be considered with reference to local safety regulations, authorities, and applicable standards.

Trolex recommends that sensors are tested with suitable test gas at regular intervals in compliance with local standards and legislation.

Following Zero and Span Tests, adjust or calibrate the sensor if necessary, or as a minimum every six months, to ensure correct operation.

SENTRO X Controller firmware can be updated in the field using a certified programming Bloc, or pBloc, where required.

The manual states that Trolex will notify users and distributors when a field firmware upgrade is needed.

Use the A/V Alarm settings to assign the LED beacon and sounder to functions such as Warning, Alarm, Fault, and Over-range.

Default A/V assignment settings are Warning off, Alarm on, Over-range on, and Fault on.

SENTRO X Ethernet supports static and dynamic configuration. Dynamic uses DHCP to retrieve IP information from the DHCP server.

If Static is selected, IP address, subnet mask, and gateway settings become available.

Use the RS485 MODBUS data settings to set the MODBUS address and configuration. The manual lists address range 1 to 255, default address 1, MODBUS RTU protocol, 2-wire half duplex RS485, and default baud rate 115200.

Parity options are even, odd, or none, with even as the default. Endianness can be big or little, with big as default, and byte swap is supported.

Use the Device settings to select the output type as either 4 to 20 mA or 0.4 V to 2 V.

The trim option allows adjustment of factory-calibrated analogue values, while Reset removes trim calibration and restores default trim settings.

Use the output assignment settings to assign SP1, SP2, SP3, STEL, TWA, Fault, and Over-range signals to available relays and indicators.

The manual states that output assignment settings are user-customisable and retained by the SENTRO X Controller.

After conditions representative of the IP rating, check the sensor for response and complete Zero and Span checks.

If SENTRO X does not respond to gas as required, a replacement Gas Inlet Cover can be fitted to uphold the IP rating.

Use Main menu > Maintenance > Remove before removing the gBloc.

The manual states that safe removal is required to avoid possible data corruption and gBloc disconnection error state.

Navigate to Main menu > Maintenance > Range and follow the on-screen instructions. The automatic output sweep can be paused and continued manually using push-button increments.

Confirm that multimeter readings at the connected equipment end match the output value shown on the SENTRO X screen.

Navigate to Main menu > Maintenance > Linearity Test and follow the on-screen instructions. Ensure the gas reading has stabilised before confirming each test point.

The test supports up to five linearity points and requires more than two target gases. The manual says Zero and Span Tests should be performed first.

Navigate to Main menu > Maintenance > Telemetry, select the required test such as relay 1A, and activate the test timer.

The test automatically ends after two minutes. Observe that the external equipment responds accordingly.

Navigate to Main menu > Maintenance > Response and follow the on-screen instructions. Start the on-screen timer at the same time as gas application and record the t90 value at the end of the test.

The manual recommends performing the Response Test after successful Zero and Span Tests.

Navigate to Main menu > Maintenance > Span Test and follow the on-screen instructions. Wait for the gas reading to stabilise, use Adjust if necessary, and save the adjusted value.

The manual notes that all gas sources have error tolerances, which should be considered during a Span Test.

Navigate to Main menu > Maintenance > Zero Test and follow the on-screen instructions.

The Zero Test checks the zero offset of the gas cell. Use the Adjust option if necessary and save the result.

Use gas from a reliable source, a regulator with a flow limit of 0.5 L/min to 1 L/min, and the SENTRO X Test Gas Hood. Turn on the regulator and ensure the target gas is flowing from the hood.

Allow the target gas to replace air in the hood for approximately 30 seconds, then place the hood over the Gas Inlet Port when prompted by the on-screen routine.

Use the Select/Confirm key hold function to access the main menu or value entry.

The menu is dynamic and changes depending on the inserted gBloc and its associated features.

Use the keypad to passively review firmware and settings information from the device information overview screens.

The manual states that no settings or outputs are affected by this review, and the screen returns to the main display if the device times out.

On power up, SENTRO X displays a splash screen, prompts for a sensing bloc if required, enters sensor warmup, and then shows the gas value screen when operating.

If no sensing Bloc is inserted within five minutes of operation, a timeout fault occurs.

The SENTRO X Controller uses two M8 fixing holes and the Remote Sensor uses two M6 fixing holes, both described as unistrut compatible.

Mount the product in the normal orientation shown in the manual and within the allowed orientation limits for the Controller and Remote Sensor.

The manual lists a 0.5 mm² four-core flexible data cable for the Controller to Remote Sensor connection.

The length is up to 10 metres where specified, or the Controller and Remote Sensor may be supplied with flexible armoured conduit/cable.

Release the four corner M4 screws, remove the blank cover to access the terminals or insert a TX6302 rBloc, and connect the required terminals using the M16 cable gland.

Use the specified four-core flexible data cable or supplied flexible armoured conduit/cable, then replace the cover and tighten the four M4 screws to 0.7 Nm.

Release the four outer M5 screws, detach the upper compartment by pulling it outwards, connect the required terminals using the M20 cable gland entries, then replace the upper compartment by docking it in-line.

Tighten the four M5 screws to 1 Nm after reassembly.

Site the sensor in consultation with specialists who understand the plant, installation, gas dispersion principles, engineering layout, and likely gas release sources.

Consider gas density or buoyancy, release pressure, ambient temperature, ventilation, and the areas where gas may accumulate.

Before commissioning and first use, inspect the product for visible damage and enclosure integrity.

The manual states that a product with damaged housing must never be used in hazardous locations.

SENTRO X installation must be carried out only by competent personnel and considered against local safety regulations and authorities.

The manual recommends EN/IEC 60079-29-2 for selection, installation, use, and maintenance guidance for flammable gas and oxygen detectors in hazardous areas.

The reset function restores stored controller settings to defaults. It deletes or restores Gas ID information, setpoints, TWA/STEL information, relay assignments, A/V assignments, MODBUS settings, Ethernet settings, analogue output mode, and saved maintenance gas values.

Factory programmed information such as serial numbers is retained, and the password is not reset to default.

The SENTRO X main menu is passcode protected by default. The manual lists the default passcode as 0000.

Trolex recommends changing this to a unique code using the Device Settings menu. Passcode protection can be disabled if required.

The main display shows gas type, gas concentration, gas units, setpoint states, TWA and STEL alarm states, alarm state overlay, and instruction bars.

The LED indicators show operating state, including green for power or gas sensing, yellow for maintenance mode, and red for alarm or fault.

Gas detector location depends on gas dispersion. The manual lists some gases as lighter than air, including hydrogen, ammonia, methane, carbon monoxide, and nitric oxide, and others as heavier than air, including oxygen, hydrogen sulphide, chlorine, and nitrogen dioxide.

Detector siting should be determined with people who understand the plant, gas source, ventilation, release pressure, ambient temperature, and gas buoyancy.

Selected toxic gas gBlocs can generate STEL and TWA setpoint signals when default or custom values are exceeded. The manual states that default values are set in accordance with EH40 standards.

Local guidelines and legislation should be consulted, and accumulated STEL/TWA data should be reset to zero before a working period if the functions are enabled.

SP1, SP2 and SP3 are gas setpoint signals defined by the gBloc Gas ID or user configuration. The manual lists default behaviour as Setpoint 1 for Warning, Setpoint 2 for Alarm, and Setpoint 3 disabled.

Setpoints can be assigned to relays, A/V Alarm functions, and MODBUS status flags depending on configuration.

Yes. The manual states that each gBloc is certified intrinsically safe and can be hot-swapped with power applied to SENTRO X at any time.

For safe removal and to avoid data corruption or disconnection error states, use the Remove Bloc function in the Maintenance menu.

A change-of-duty occurs when a gBloc of a different gas type or range is installed. SENTRO X displays a comparison screen and asks the user to confirm the intent.

If Change-of-Duty is confirmed, SENTRO X loads the default Gas ID settings from the new gBloc and retains the new settings until reset.

On first installation, the SENTRO X Controller accepts the default Gas ID information dictated by the inserted gBloc.

If a like-for-like replacement gBloc is installed, the controller accepts it and immediately functions in the normal way.

SENTRO X is designed to operate from a 9.5 V DC to 16 V DC approved intrinsically safe source, with nominal operation at 12 V DC.

The controller includes an active power supply input and can safely function down to 9.5 V DC by automatically adjusting current demand.

The TX6310 SENTRO X Controller, TX6320 Remote Sensor, Gas Inlet Port, and A/V Alarm are listed with IP65 ingress protection.

The manual also notes that the IP rating does not imply that the equipment will detect gas during and after exposure to those conditions; response checks are recommended after such exposure.

The SENTRO X technical specification lists an operating temperature range of -20 °C to +40 °C and storage temperature limits of -20 °C to +60 °C.

The product must be operated within the technical and certification limits described in the manual.

The intrinsically safe Ethernet Card allows SENTRO X data to be exchanged with wide area remote monitoring systems and SCADA networks.

The Ethernet Card occupies Slot B only. If it is fitted, only one Dual Relay Card can be fitted in Slot A.

The Dual Relay Card provides two independent encapsulated reed relays, each with an isolated changeover output contact for switching approved intrinsically safe circuits.

Up to two Dual Relay Cards can be fitted, one in Slot A and one in Slot B, depending on the configured extension options.

The optional A/V Alarm is an intrinsically safe local warning device fitted to the SENTRO X Controller. It includes high-brightness red flashing LEDs and an audio warning rated at 86 dB peak at 1 metre.

The beacon and sounder can be assigned through the menu to warning, alarm, fault, and over-range functions.

SENTRO X provides RS485 MODBUS, analogue output configurable as 4 to 20 mA or 0.4 V to 2 V, and optional relay outputs through Dual Relay Cards.

It can also be supplied with an optional intrinsically safe A/V Alarm and an optional intrinsically safe Ethernet Card.

The manual lists approved gBlocs for chlorine, carbon monoxide, hydrogen, hydrogen sulphide, ammonia, nitric oxide, nitrogen dioxide, oxygen, sulphur dioxide, methane, and carbon dioxide.

The available measuring range depends on the fitted gBloc type and order code.

A gBloc is a pre-calibrated smart gas sensing module used with the SENTRO X Controller or Remote Sensor. Each gBloc contains intelligent data storage, signal conditioning, and Gas ID information.

gBlocs are available for oxygen, toxic gases, and flammable gases, depending on the certified option and gas range.

The TX6320 Remote Gas Sensor is a rugged remote sensor head for locations that are restrictive, inaccessible, or less convenient for controller access.

Data from the remote sensor is transmitted to the SENTRO X Controller, which can be mounted up to 10 metres away from the gas detection area.

The TX6310 SENTRO X Controller is the main programmable controller in the SENTRO X Gas Detector suite. It includes an OLED graphic display, keypad, integral output signals, and optional extension cards.

Depending on configuration, it can house an integral gas sensing gBloc or interface with a remote sensor head.

SENTRO X is a gas detector platform built around the TX6310 SENTRO X Controller. The controller houses the main intelligence of the gas detection system and can operate with an integral gBloc gas sensor or with a TX6320 Remote Gas Sensor.

The manual describes SENTRO X as certified to Group I, M1 intrinsically safe standards and intended for underground hazardous areas and heavy industrial applications.