TECHSOFT APS-DD-2

Description

Technical Specifications:

• Model: APS-DD-2
• Channels: 2 independent channels (input or output configurable)
• Input Range (Voltage): 0–10 VDC, ±10 VDC, 0–5 VDC (jumper selectable)
• Input Range (Current): 0–20 mA, 4–20 mA (jumper selectable)
• Output Range (Voltage): 0–10 VDC, ±10 VDC (software configurable)
• Output Range (Current): 0–20 mA, 4–20 mA (software configurable)
• Resolution: 16-bit ADC / 16-bit DAC
• Accuracy: ±0.1% of full scale
• Isolation: 1500 VDC channel-to-channel, channel-to-ground
• Sampling Rate: Up to 10 kS/s per channel
• Power Supply: 24 VDC ±10%
• Power Consumption: < 2 W
• Operating Temperature: -10°C to +60°C
• Dimensions: 90 mm × 60 mm × 25 mm (DIN-rail mount)
• Communication: RS-485 Modbus RTU, baud rate 9600–115200 bps
• Protection: Overvoltage, reverse polarity, surge protection (IEC 61000-4-5)

Functional Features:

• Each channel independently configurable as input or output
• Software-calibrated zero and span adjustment
• Diagnostic LED per channel (power, communication, fault)
• Watchdog timer for fail-safe output
• Modbus register map for remote configuration

Structural Characteristics:

• Housing: ABS plastic or metal DIN-rail enclosure (IP20)
• Terminals: Screw terminals, 3.5 mm pitch, 2.5 mm² max wire
• Mounting: 35 mm DIN rail (EN 60715) or panel mount with brackets
• PCB: 4-layer, isolated power sections per channel

Working Principle: The analog input signal is conditioned through an instrumentation amplifier, filtered by an anti-aliasing low-pass filter (cutoff 5 kHz), then digitized by a 16-bit sigma-delta ADC. The digital value is transmitted via RS-485 Modbus. For output mode, a 16-bit DAC generates the analog signal, which is buffered by a precision op-amp and isolated by an optocoupler or transformer before reaching the output terminals.

Advantages:

• Dual independent channels with full galvanic isolation
• Flexible input/output configuration per channel
• High resolution and accuracy for process control
• Compact form factor for space-constrained panels

Applicable Industries: Process control, SCADA systems, building automation, water/wastewater treatment, HVAC control

Installation Requirements:

• DIN rail TS 35, 7.5 mm or 15 mm width
• 24 VDC power supply with < 5% ripple
• RS-485 bus: terminated with 120 Ohm resistor at each end, max 32 devices per bus
• Cable shielding grounded at one end only

Usage Precautions:

• Do not exceed input voltage range — will damage ADC
• Verify jumper settings before powering on (input vs. output mode)
• Ensure proper RS-485 termination to prevent communication errors
• Do not connect outputs in parallel without isolation