913MB /914MB

Key Features:

This 913MB/914MB is a signal conditioner supporting the Modbus RTU protocol and equipped with four-channel analog input module and four discrete outputs. Designed to provide 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% of range resolution and accuracy
• Four inputs in a single inch-wide module reduces system costs and saves panel space
• Four discrete outputs enable local 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
• Operating temperature: -25°C to +70°C (-13°F to +158°F).

Product Details

General Input

– 0.005% or 1 part in 20,000.
Noise Rejection
– Normal mode: 40dB @ 60Hz, typical.
– Common mode: 140dB @ 60Hz, typical.
Input Filter Bandwidth
– -3dB at 3Hz, typical.
Input Conversion Rate
– 180ms per channel.

Current Input (913MB)

DC Current Input Ranges
– Range user-configured. Range selected applies to all channels.
– 0 to 1mA, 0 to 20mA, 4 to 20mA,
– 0 to 11.17mA (for use with 5020-350 AC sensor).
DC Current Input Resistance
– 49.9 ohms.
DC Current Input Accuracy
– ±0.1% of input range.

Voltage Input (914MB)

DC Voltage Input Ranges
– Range user-configured. Range selected applies to all channels.
– ±10V, ±5V, ±2.5V, ±1.25V,
– ±625mV, ±313mV, ±156mV, ±78mV
Input Impedance
– 110.5K ohms.
DC Voltage Input Accuracy
– ±0.1% of input range.

Discrete Output

Output Type
– Four independent open drain MOSFET switches with a common return that operate as low-side switches.
Output Voltage Range
– 0 to 35V DC.
– External voltage source required.
Output Current Range
– 0 to 1A DC continuous for each output.
Output OFF Leakage Current
– 50µA maximum.
Output ON Resistance
– 0.15 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 Coil (Output) Status
– Read Holding Registers
– Read Input Registers
– Force Single Coil (Output)
– Preset Single Register
– Force Multiple Coils (Output)
– Preset Multiple Registers
– Report Slave ID
– Reset Slave
LED Indicators
– LEDs indicate power, status, and discrete level/alarm.

Power and Isolation

Power Requirements
– 10 to 36V DC or 22 to 26V AC.
Supply Current
– Supply Current Draw
– 10V DC 125mA maximum
– 24V DC 50mA maximum
– 24V AC 100mA rms maximum
– 1500V AC for 60 seconds or 250V AC continuous.
– 4-way isolation between input, network, power, anddiscrete I/O circuits. Inputs are isolated channel-tochannel for common mode voltage to ±4V DC.