Foxboro RH924WA Dual-Input Panel-Mount Recorder with Quad Alarm

Technical Specifications:

• Input Channels: 2 universal inputs (independent)
• Input Types: Type J, K, T, E, S, R, B TC; Pt100, Pt1000 RTD; 4–20 mA; 0–10 V; 1–5 V
• Display: Dual-line 6-digit red LED, 14 mm digits, 100,000 count
• Recording Memory: 8000 data points per channel with date/time stamp
• Recording Interval: 1 s to 60 s (configurable)
• Alarm Outputs: 4 SPDT relays (2 Hi + 2 Lo per channel), 250 V AC / 30 V DC, 3 A
• Communication: RS-485 Modbus RTU, 9600–38400 baud
• Retransmission: Isolated 4–20 mA per channel
• Power Supply: 85–265 V AC / 90–300 V DC / 24 V DC
• Operating Temperature: -10°C to +55°C (+14°F to +131°F)
• Protection Rating: IP65 front panel
• Dimensions: 96 mm x 96 mm x 93 mm (W x H x D)
• Cutout Size: 92 mm x 92 mm
• Weight: Approximately 460 grams

Functional Features:

• 8000-Point Trend Recording: Non-volatile EEPROM with full timestamp per channel
• 4 Alarm Relays: 2 Hi and 2 Lo per channel with independent hysteresis
• Data Download: Trend data downloadable via RS-485 Modbus to host system
• Latching Alarms: Relays latch until manually reset
• 24 V Loop Power: Provides loop power to 2-wire transmitters (max 600 Ω)

Material Composition:

• Front Bezel: Flame-retardant ABS, matte black
• Housing: Polycarbonate (Lexan), IP65 gasket-sealed
• Display: High-brightness red LED, optical-grade polycarbonate
• Terminals: Phosphor bronze, nickel-plated

Structural Characteristics:

• Form Factor: 96 x 96 mm panel-mount (1/4 DIN)
• Keypad: 8-button membrane with recording and alarm menus
• Communication: RJ-11 jack, rear-mounted
• Memory: Non-volatile EEPROM — data retained during power loss

Working Principle:
Each channel’s signal is digitized by a 24-bit ADC and stored in EEPROM at the configured interval with a real-time clock timestamp. The current value is displayed on the dual LED lines. Four alarm comparators per unit (2 Hi, 2 Lo per channel) continuously monitor the process values against user-set setpoints with independent hysteresis. When crossed, the corresponding SPDT relay latches. RS-485 Modbus enables remote data retrieval and alarm status polling.

Advantages / Highlights:

• Combines recording and quad-alarm in a single 96 x 96 mm instrument
• 8000-point non-volatile memory provides extensive trend history
• 4 latching alarm relays ensure no alarm condition is missed
• Modbus RTU enables seamless DCS/SCADA integration
• IP65 rated for washdown and outdoor panel use

Applicable Industries:

• Oil and Gas (production monitoring, safety systems)
• Chemical Processing (batch monitoring, alarm management)
• Power Generation (equipment protection)
• Pharmaceutical (GMP trend recording)
• Food and Beverage (HACCP monitoring)

Installation Requirements:

• Cut 92 mm x 92 mm panel opening
• Mount with IP65 gasket and snap-in clips
• Wire Ch1 and Ch2 inputs to respective terminal blocks
• Connect 4 alarm relays to AL1-H, AL1-L, AL2-H, AL2-L, AL3-H, AL3-L, AL4-H, AL4-L
• RS-485: A, B, GND with 120 Ω termination at bus ends
• Power: 85–265 V AC or 24 V DC

Usage Precautions:

• Verify recording interval — at 1 second interval, 8000 points = ~2.2 hours of data
• Do not power cycle during recording — risk of EEPROM corruption
• Test all 4 alarm relays using keypad test function before commissioning
• Do not exceed 600 Ω loop resistance per channel
• Set Modbus address uniquely for each device on the RS-485 bus