Honeywell TPWM4422 Gas Detection Input Module Unit

Module Feature

TPWM4422 is a field replaceable plug-in channel module for Honeywell Touchpoint 4 gas detection controller platform. Channel configuration: 2 channels for 2/3-wire 4-20mA transmitters, 2 channels for mV catalytic bead / electrochemical bridge sensors such as Sensepoint flammable detectors. Each independent channel has two SPCO alarm relays, configurable latching/non-latching, energise/de-energise on alarm. It exchanges measurement data, fault signals and alarm status with the Touchpoint4 main board via internal backplane bus. It supports gas concentration retransmission, sensor fault monitoring and remote access through host software. The Touchpoint4 series is obsolete, this module is widely stocked as maintenance spare for legacy gas safety cabinets.

Working principle

The module samples analog signals from field gas detectors: 4-20mA current signal or millivolt bridge voltage. The on-board ADC converts raw analog data to digital readings, compares against user-programmed alarm setpoints. If concentration exceeds threshold, the local relay activates, and alarm event is sent to the Touchpoint4 main unit and upper SCADA via Modbus. Continuous sensor health supervision runs in parallel to report open circuit, short circuit and signal out-of-range faults.

Onboard components

Analog signal conditioning circuit, ADC chip, backplane communication interface, isolated signal protection circuit, dual alarm relay per channel, surge suppression components, status LED array, edge backplane connector and terminal block assembly.

LED indicators

Front LEDs indicate channel healthy, pre-alarm, high alarm, sensor fault and module communication failure.

Hardware self‑diagnosis

Built-in supervision monitors sensor cable open / short, signal out of range, module supply loss and backplane communication drop-out. All fault codes and event logs are displayed on the Touchpoint4 main HMI.

Programming software

Honeywell Touchpoint 4 configuration software, used for gas type selection, alarm threshold setup, relay logic definition and Modbus register mapping.

Electrical & Process Parameters

Model:TPWM4422 Brand:Honeywell Analytics Device type:Mixed mA/mV gas input plug-in module Function:Gas signal acquisition, concentration calculation and alarm output for gas detectors

Mechanical & Structure

Mounting:Slot plug-in installation inside Touchpoint4 controller chassis Protection class:IP20 (internal, protected by controller enclosure) Housing:PCB assembly with metal front panel

Environmental

Operating temperature:-10℃ ~ +40℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:ATEX, IECEx, CE

Status:Obsolete original Honeywell gas detection spare

Installation

Cut off Touchpoint4 controller power before module insertion or removal. Route field detector wiring to the corresponding channel terminals, select correct input type (mA or mV) and set alarm parameters before commissioning.

Interface

Field sensor input terminals, alarm relay dry contact outputs, internal backplane bus connector.

Diagnostic

Channel fault warning: Field cable open/short, detector power loss or reversed polarity. No valid gas reading: Mismatched input type selected (mA/mV), failed sensor or defective module channel. Relay fails to trigger: Alarm setpoint not reached, relay logic misconfigured or output wiring broken.

Product Brief

Honeywell TPWM4422 gas input module, Touchpoint4 2mA+2mV mixed channel spare card for hazardous area flammable and toxic gas detection cabinet replacement.