Foxboro RH926GK Quad-Input Panel-Mount Recorder

Technical Specifications:

• Input Channels: 4 universal inputs (independent configuration)
• Input Types: Type J, K, T, E, S, R, B TC; Pt100, Pt1000 RTD; 4–20 mA; 0–10 V; 1–5 V
• Display: Quad-line 6-digit red LED, 14 mm digits, 100,000 count per line
• Recording Memory: 4000 data points per channel with date/time stamp
• Recording Interval: 1 s to 60 s (configurable)
• Alarm Outputs: 2 SPDT relays per channel (8 total), 250 V AC / 30 V DC, 3 A
• Communication: RS-485 Modbus RTU, 9600–38400 baud
• Retransmission: Isolated 4–20 mA per channel (optional)
• 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 98 mm (W x H x D)
• Cutout Size: 92 mm x 92 mm
• Weight: Approximately 520 grams

Functional Features:

• 4 Independent Channels: Simultaneous monitoring of 4 process variables on a single instrument
• Quad-Line Display: All 4 values visible simultaneously on 4 LED lines
• 4000-Point Recording Per Channel: Non-volatile EEPROM with timestamp
• 8 Alarm Relays: 2 per channel with independent setpoints and hysteresis
• RS-485 Modbus RTU: Full DCS/SCADA integration
• 24 V Loop Power: Per channel (max 600 Ω per channel)

Material Composition:

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

Structural Characteristics:

• Form Factor: 96 x 96 mm panel-mount (1/4 DIN)
• Display Layout: Line 1 = Ch1, Line 2 = Ch2, Line 3 = Ch3, Line 4 = Ch4
• Keypad: 10-button membrane with channel navigation
• Communication: RJ-11 jack, rear panel

Working Principle:
Four independent 24-bit ADCs digitize the four input channels simultaneously. Each channel’s value is displayed on its dedicated LED line. Values are stored in 4000-point EEPROM memory per channel at the configured recording interval with timestamp. Each channel has 2 alarm comparators driving SPDT relays. RS-485 Modbus RTU provides communication with the host system. The microcontroller cycles through channel display and allows per-channel configuration via the keypad.

Advantages / Highlights:

• 4-channel monitoring in one 96 x 96 mm instrument — maximizes panel space efficiency
• 8 alarm relays provide comprehensive protection across all 4 channels
• Quad-line display enables at-a-glance monitoring of all variables
• Modbus RTU enables integration with any Modbus-compatible DCS/SCADA
• IP65 rated for harsh environment deployment

Applicable Industries:

• Oil and Gas (wellhead monitoring, manifold monitoring)
• Chemical Processing (reactor monitoring, multi-stream tracking)
• Power Generation (multi-zone temperature monitoring)
• Water Treatment (multi-point quality monitoring)
• HVAC (multi-zone control)

Installation Requirements:

• Cut 92 mm x 92 mm panel opening
• Mount with IP65 gasket and snap-in clips
• Wire 4 channel inputs to Ch1, Ch2, Ch3, Ch4 terminal blocks
• Connect 8 alarm relays to AL1-H/L through AL8-H/L terminals
• RS-485: A, B, GND with 120 Ω termination at bus ends
• Power: 85–265 V AC or 24 V DC
• Set unique Modbus address for each RH926GK on the bus

Usage Precautions:

• Maximum 4 channels simultaneously — do not exceed 4 input connections
• Total power consumption increases with 4 channels — verify power supply capacity
• Do not apply > 50 V DC to any mA/V input terminal
• Test all 8 alarm relays using keypad test before commissioning
• Recording memory per channel is 4000 points — configure interval accordingly

11. FOXBORO RH927AH

Product Name: Foxboro RH927AH Quad-Input High-Accuracy Panel Recorder with 8 Alarms

Product Series: Foxboro RH900 Series — Premium Multi-Channel Recorder

Product Introduction:
The RH927AH is the premium quad-input (4-channel) panel-mount recorder and indicator in the Foxboro RH900 series. It features high-accuracy measurement (±0.05% of span), 16,000-point recording memory per channel, 8 independent alarm relays (2 per channel), HART and RS-485 Modbus RTU communication, and an extended-depth housing to accommodate the enhanced electronics. It is designed for the most demanding process monitoring applications.

Technical Specifications:

• Input Channels: 4 universal inputs (independent, high-accuracy)
• Input Types: Type J, K, T, E, S, R, B TC; Pt100, Pt1000 RTD; 4–20 mA (HART); 0–10 V; 1–5 V
• Display: Quad-line 6-digit red LED, 14 mm digits, 200,000 count resolution
• Accuracy: ±0.05% of span (mA/V); ±0.2% of span (TC/RTD)
• Recording Memory: 16,000 data points per channel with full date/time stamp
• Recording Interval: 0.5 s to 60 s (configurable)
• Alarm Outputs: 8 SPDT relays (2 Hi + 2 Lo per channel), 250 V AC / 30 V DC, 3 A each
• Communication: HART 7 + RS-485 Modbus RTU
• Retransmission: Isolated 4–20 mA per channel (HART pass-through)
• 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 105 mm (W x H x D) — extended depth
• Cutout Size: 92 mm x 92 mm
• Weight: Approximately 580 grams

Functional Features:

• High-Accuracy 24-Bit ADC: 200,000 count resolution, ±0.05% accuracy
• 16,000-Point Recording Per Channel: The largest memory in the RH900 series
• 8 Programmable Alarms: 2 Hi and 2 Lo per channel with independent hysteresis (0.1% to 20% of span)
• HART Communication: Configure and diagnose HART field devices
• Modbus RTU: Full DCS/SCADA integration
• Latching Alarms: All 8 relays latch until manually reset

Material Composition:

• Front Bezel: Flame-retardant ABS, precision-molded matte black
• Housing: Polycarbonate (Lexan), IP65 gasket-sealed, extended depth for enhanced electronics
• Display: High-brightness red LED, optical-grade polycarbonate, anti-reflective coating
• Terminals: Phosphor bronze, gold-plated for high-accuracy signal integrity
• PCB: FR-4 with gold-plated traces on critical analog signal paths

Structural Characteristics:

• Form Factor: 96 x 96 mm panel-mount (1/4 DIN), 105 mm depth (deeper than standard RH900)
• Display Layout: 4 lines — Ch1 (top), Ch2, Ch3, Ch4 (bottom)
• Keypad: 12-button membrane with full HART, recording, and alarm configuration
• Connectors: RJ-11 (RS-485), screw terminals (HART), screw terminals (power/I/O)

Working Principle:
Four independent 24-bit sigma-delta ADCs sample each channel at high resolution. The microcontroller applies per-input-type linearization and stores values in 16,000-point EEPROM with real-time clock timestamp at the configured interval (minimum 0.5 s). HART communication decodes diagnostics from HART-enabled transmitters. Eight alarm comparators (2 Hi, 2 Lo per channel) with independent hysteresis drive 8 SPDT latching relays. RS-485 Modbus RTU provides standard digital communication with the DCS/SCADA host.

Advantages / Highlights:

• ±0.05% accuracy — the highest precision in the entire RH900 series
• 16,000 points per channel — longest trend recording in the series
• 8 alarm relays — most comprehensive alarm coverage in RH900 series
• HART + Modbus dual communication — full field device and DCS integration
• Gold-plated terminals — ensures signal integrity for high-accuracy applications
• Extended-depth housing — accommodates enhanced electronics and memory

Applicable Industries:

• Oil and Gas (custody transfer, fiscal metering, safety systems)
• Chemical Processing (precision dosing, reaction monitoring)
• Power Generation (boiler/turbine protection, emissions monitoring)
• Pharmaceutical (GMP-compliant high-accuracy monitoring)
• Semiconductor Manufacturing
• Nuclear Power (safety-critical monitoring)

Installation Requirements:

• Cut 92 mm x 92 mm panel opening — ensure 105 mm minimum depth behind panel
• Mount with IP65 gasket and snap-in clips
• Use shielded twisted pair cable for all analog and HART connections
• RS-485: A, B, GND with 120 Ω termination at bus ends (max 32 devices)
• HART: ensure 250 Ω loop resistor in the DCS I/O card
• Power: 85–265 V AC or 24 V DC
• Set unique Modbus address (1–247) via DIP switches

Usage Precautions:

• Do not apply > 50 V DC to any mA/V input terminal
• HART requires 250 Ω loop resistor — verify before connecting HART devices
• Calibration verification recommended every 12 months to maintain ±0.05% accuracy
• Do not open housing during operation — voids accuracy specification and creates shock hazard
• At 0.5 s recording interval, 16,000 points = ~2.2 hours per channel — configure interval to match retention needs
• Total power draw is higher than standard RH900 models — verify power supply capacity