932MB / 934MB

Key Features:

This signal conditioner is a dual or quad-channel analog input module with one discrete/relay output per input channel and a Modbus interface designed to filters and linearizes RTD or resistance inputs while providing isolation between input, output, power, and network circuits.

• Standard Modbus RTU protocol with high-speed RS-485 communication (up to 115K bps)
• 16-bit sigma-delta A/D yields 0.1°C resolution and 0.25°C accuracy (Pt, Ni RTDs)
• RTD linearization and sensor break detection ensure reliable measurements
• Discrete relay outputs enable local temperature limit alarms or host-controlled on/off switching
• Heavy-duty 1A solid-state relays provide dependable on/off control of industrial devices
• Self-calibration lowers maintenance costs by reducing periodic manual calibration checks
• Watchdog timers provide a configurable failsafe output state for use when host I/O communication is lost
• Four-way isolation eliminates potential ground loops between power, input, output and network circuitry
• Self-diagnostics monitor microcontroller activity to detect operational failures (lock-up) and execute a reset to restore communication

Product Details

RTD/Resistance Input

– RTD (100 ohm Pt, 120 ohm Ni, 10 ohm Cu),
– Resistance (0 to 500 ohms)
Ambient Temperature Effect
– Better than ±0.005% of input span per °C, or ±1.0uV/°C, whichever is greater.
Noise Rejection
– Normal mode: 40dB @ 60Hz, typical.
– Common mode: 130dB @ 60Hz, typical.
Input Filter Bandwidth
– -3dB at 3Hz, typical.
Input Conversion Rate
– 300ms per channel typical.
RTD Break Detection
- Sensor failure can be configured for either upscale or downscale. Selection applies to all channels.
Excitation Current
– 1mA DC typical, all types.
Lead-Wire Compensation
– Inherent for 3-wire RTD.
– The maximum lead resistance is 25 ohms per lead (Pt), 20 ohms per lead (Ni), 10 ohms per lead (Cu). All lead wires must be of equal size and length.

Discrete Output

Output Type
– Solid-State Relay (SSR), one Form A (SPST-NO) switch per input channel. Outputs share a common return connection at the RTN terminals for low side switching
Output Voltage Range
– 0 to 48V DC, 1A DC.
Output ON Resistance
- 0.4 ohms maximum.
Output Response Time
– 4.1ms typical, from receipt of command to gate transition of the output MOSFET.


Supported Modbus Commands
The command/response protocol for communicating with this module adheres to the Modbus/RTU standard for the following Modbus Functions.
• Read Holding Registers Read Coil
• Read Input Registers Reset Slave
• Preset Single Register Report Slave ID
• Force Multiple Coils Force Single Coil
• Preset Multiple Register
LED Indicators
- LEDs indicate power, status, and discrete level/alarm.

Power and Isolation

Power Requirements
– 10 to 36V DC (56mA max. at 24V DC).
– 22 to 26V AC (94mA rms max. at 24V AC).
– 1500V AC for 60 seconds or 250V AC continuous.
– 4-way isolation between input, network, power and discrete I/O circuits. Inputs are isolated channel-to channel for common mode voltage to ±5V DC.