Technical Specifications:

• Module Type: Analog Input (Current)
• Number of Channels: 8 channels
• Input Signal: 4–20 mA DC (2-wire transmitters)
• Input Impedance: 250 Ω (burden resistor built-in)
• Resolution: 12-bit (4096 steps)
• Conversion Accuracy: ±0.1% of Full Scale (FS)
• Sampling Time: 10 ms per channel (total scan: 80 ms for 8 channels)
• Common Mode Rejection Ratio (CMRR): ≥ 80 dB at 50/60 Hz
• Isolation Voltage: 500 VDC (channel-to-channel, channel-to-bus)
• Power Supply: 5 VDC from PLC backplane bus
• Current Consumption: 180 mA (typ.) from backplane
• Operating Temperature: 0°C to +55°C (+32°F to +131°F)
• Dimensions (W × H × D): 25 mm × 90 mm × 85 mm
• Weight: Approximately 0.1 kg

Functional Features:

• 8 independent channels with individual scaling (engineering units, range, damping)
• Built-in 250 Ω burden resistor — no external resistor required for 2-wire transmitters
• Channel-to-channel isolation prevents ground loop interference
• On-line module replacement (hot-swap capable in F4 series)
• LED indicators per channel for signal presence detection

Structural Features:

• Standard F3/F4 module form factor
• DIN rail mountable in PLC rack
• Screw-terminal block connector for all 8 input channels (2 wires per channel: + and -)
• Isolation barrier between field side and bus side

Working Principle:
Each of the 8 input channels receives a 4–20 mA signal from a 2-wire field transmitter. The current flows through the built-in 250 Ω burden resistor, developing a 1–5 VDC voltage proportional to the current. This voltage is fed to a 12-bit A/D converter. The digital result is scaled to engineering units (e.g., °C, PSI, %) using parameters set in the PLC CPU and stored in the module’s register. The isolated digital data is transferred to the CPU via the backplane bus.

Advantages & Highlights:

• Built-in 250 Ω burden eliminates external components — reduces wiring and cost
• 12-bit resolution provides fine measurement granularity (4096 steps)
• ±0.1% FS accuracy meets most process control requirements
• Channel isolation eliminates cross-talk and ground loop errors
• 8 channels in one module — reduces rack space and cost vs. single-channel modules

Applicable Industries:

• Chemical process control
• Oil and gas (wellhead, pipeline monitoring)
• Water and wastewater (flow, level, pressure)
• Power plant (temperature, pressure, flow)
• Food and pharmaceutical (batch control)

Installation Requirements:

• Insert into F3/F4 PLC rack at the designated slot
• Connect 2-wire transmitter loop: transmitter (+) to module input (+), transmitter (-) to module input (-)
• Use shielded twisted-pair cable for all analog inputs
• Connect the shield to earth ground at one end only (DCS/PLC side)

Usage Precautions:

• Do not apply voltage signals (0–10 V, 0–5 V) to current input terminals — will damage the module
• Maximum loop resistance (transmitter + wiring) must not exceed 600 Ω at 24 VDC supply
• Do not leave input channels unconnected — floating inputs cause erratic readings
• Perform zero calibration (4 mA = 0%, 20 mA = 100%) after installation