Technical Specifications – Serial Module​

System: Honeywell ControlEdge HC900

Ports: two RS-232 and two RS-485

Protocols: Modbus RTU master or slave, user-defined serial protocol

Data format: 7 or 8 data bits, odd, even, or none parity, 1 or 2 stop bits where supported

Isolation: electrical isolation for industrial communication

Dimensions: 137 mm height, 35.6 mm width, 25 mm depth

Weight: 0.45 kg

Mounting: DIN rail or panel mount

Operating temperature: -20°C to +60°C

Certifications: CE, UL, CSA

Technical Specifications – Pressure Transmitter​

Range: 0 to 100 PSI gauge, 0 to 6.9 bar

Output: 4 to 20 mA two-wire

Accuracy: ±0.25% full scale

Supply voltage: 12 to 36 VDC

Process connection: 1/2 NPT male

Wetted diaphragm: 316L stainless steel

Internal wetted parts: Hastelloy C-276

Enclosure: NEMA 4X, IP66

Response time: less than 10 ms to 90% step

Overpressure: 150% full scale

Burst pressure: 300% full scale

Operating temperature: -40°C to +85°C

Electrical entry: 1/2 NPT with cable gland

Functional Features​

The serial module bridges HC900 controllers to transmitters, analyzers, and legacy instruments using Modbus or custom messaging. The pressure transmitter provides loop-powered 4 to 20 mA output with diaphragm strain measurement and electronic linearization.

Application Scenarios​

Serial module: HC900 process control, legacy instrument integration, analyzer communication, Modbus RTU networks. Pressure transmitter: HVAC, building automation, water and wastewater, compressed air, and general process pressure monitoring.

Material And Structure​

The serial module uses a molded industrial housing with isolated transceivers and DIN/panel hardware. The pressure transmitter uses a 316L diaphragm, Hastelloy internals, stainless process nipple, and NEMA 4X enclosure.

Working Principle​

The serial module converts controller data into RS-232 or RS-485 frames and manages receive, transmit, and protocol validation. The pressure transmitter deflects the diaphragm under process pressure, measures strain with a conditioned bridge circuit, and outputs a linear 4 to 20 mA signal.

Installation Requirements​

For the serial module, mount on the HC900 rack or DIN rail, assign RS-232 or RS-485 ports in configuration software, and use shielded serial cable with proper grounding. For the pressure transmitter, mount the process connection downward for liquid service, use 1/2 NPT sealing, power with 12 to 36 VDC, and keep loop resistance within the supply headroom.

Usage Precautions​

Do not interchange the serial and pressure versions by part number alone; verify the controller bill of material. For the serial module, confirm Modbus data-bit and parity settings before commissioning. For the pressure transmitter, perform zero calibration after installation, do not exceed 150 PSI working overpressure, and use shielded twisted pair sized for loop current and supply voltage.